Full opinion text
MOORE, Circuit Judge: This extraordinarily protracted litigation is the unfortunate aftermath of a labor strike that commenced some fifteen years ago. Lodge 743, International Association of Machinists and Aerospace Workers, AFL-CIO, is the collective bargaining agent for employees at the Windsor Locks and Broad Brook plants of the Hamilton Standard Division of United Aircraft Corporation; Lodge 1746 represents workers at the East Hartford and Manchester plants of the Pratt & Whitney Aircraft Division of the same Company. These two Lodges will be referred to collectively as the “Union.” Pratt & Whitney engages primarily in the manufacture of aircraft engines; Hamilton Standard manufactures primarily aircraft propellers, aircraft engine fuel controls and air conditioning systems, and electronic components, controls and related items. In 1960, when the principal events involved in this litigation transpired, the four plants together employed nearly 20,000 people. On June 8, 1960, the Union struck these four plants (the International Association struck at other United Aircraft plants in the State of Connecticut as well) over demands sought to be included in a new collective bargaining agreement. The strike lasted nine weeks and was marked by extreme violence and mutual antipathy. It was not settled until Abraham Ribicoff, the Governor of Connecticut, intervened in an effort to induce the parties to reach an accommodation. As the basis of the strike settlement, the Company and the Union reached accord on new collective bargaining contracts covering workers at the four plants and also agreed to submit to arbitration the cases of 50 strikers accused of serious misconduct. In addition, they agreed on a procedure to govern the recall of strikers to jobs at the four plants. The terms of this agreement were set down in writing by the Company and became embodied in two similar although not wholly identical documents, one covering employees of Pratt & Whitney and the other employees of Hamilton Standard. These documents, each denominated in its caption as a “Strike Settlement Agreement” (herein sometimes termed the “recall” Agreements), are the root of these cases. Being totally dissatisfied with what ensued with respect to the recall Agreements, the Union sought two avenues of redress. Commencing in November 1960, the Union filed with the NLRB a battery of unfair labor practice charges relating mainly to the Company’s allegedly unlawful administration of the recall Agreements and its refusals to supply the Union with certain requested information. On February 7, 1963, the General Counsel of the NLRB issued a consolidated complaint based on the Union’s charges. A hearing before a Trial Examiner commenced in 1963 and lasted, with numerous intermittent recesses, until June 1968. In the meantime, the Union had also filed suit under Section 301 of the Labor Management Relations Act, 29 U.S.C. § 185, in the United States District Court for the District of Connecticut. The complaints (two suits were eventually consolidated for trial), filed December 11, Í961, alleged breach of the Strike Settlement Agreements and sought specific performance as well as substantial monetary damages. The case ground through discovery, several interlocutory rulings, and a 4V2 month trial, and on March 20, 1969, the district court issued a lengthy decision (reported at 299 F.Supp. 877, D.C.Conn.) largely in favor of the defendant, although it did find that the Company breached the agreements in some limited respects. The case then proceeded through a determination of the question of damages to final judgment dated June 16, 1972. The judgment incorporated by reference the findings of fact and conclusions of law set forth in the Court’s opinion (Memorandum of Decision filed March 20, 1969) and, more specifically as to damages, directed the defendant to pay to plaintiff Lodge 743 and plaintiff Lodge 1746 for distribution to beneficiaries, identified in an appendix annexed to the judgment, amounts described as “Net Monetary Damages” plus interest at 6% from March 20, 1972 (the date of the opinion) except for a deduction therefrom of 15% of the amounts stated which percent was to be paid to the unions for the benefit of retained counsel in the litigation. Other items by way of payment to unemployment compensation and pension funds as well as other employee adjustments were specified. Claims of all employees except 72 specified in the Appendix were denied and the complaint was dismissed as to them. Legal taxable costs were awarded to plaintiffs. Four categories of striker-employees held to have been prejudiced by defendant’s actions were listed with the name and specific damage award, together with other benefits where appropriate. These were (a) Strikers Prejudiced by Transfers, Promotions or Demotions Into Jobs Vacated by “Summer” Employees; (b) Strikers Prejudiced by Promotions; (c) Strikers Prejudiced by Transfer of “Department 74 Trainees” and (d) Strikers Prejudiced by Lateral Transfers and Demotions From One Seniority Group to Another. The judgment of the district court has not been appealed with respect to all of these categories. See note 25 infra. On July 25, 1969, the Trial Examiner handed down his ruling in the unfair labor practice proceedings. He concluded that, except in narrow areas paralleling the findings of the district court in the section 301 case, the Company had committed no unfair labor practices in connection with the recall of strikers during the life of the Agreements. He did find, however, that the Company’s treatment of unrecalled strikers following the life of the recall agreements did deny them certain rights under the National Labor Relations Act. The Examiner also dismissed' Section 8(a)(5) charges that the Company had refused to bargain in good faith by withholding certain information from the Union. The other limited findings of the Trial Examiner will be considered in due course. On review, the Board adopted the decision of the Trial Examiner with some modification, including a reversal of the Trial Examiner’s ruling that the Company had denied the strikers certain rights after the expiration of the recall Agreements. United Aircraft Corp., 192 NLRB 382 (1971). From these rulings the parties seek review. The Union appeals the district court’s ruling in the section 301 suit, claiming that the court erred in nearly all significant respects. The Company also cross appeals with respect to some of the matters determined adversely to it (Nos. 72-1936, 72-1937, 72-2072). In the NLRB proceedings, the Unions have petitioned for review and the Board has cross-petitioned for enforcement of its order against the Company. The Union has also intervened in the enforcement proceeding (Nos. 72-1935, 72-2310). These cases were argued together and, although dealt with separately in this opinion, are inextricably intertwined. I. The Section 301 Suit A. General Introduction The Strike Settlement Agreements called for strikers desiring to return to work to express their intention by registering. Under the terms of the Agreements registration would take place at Hamilton Standard on August 9 and 10, 1960, and at Pratt & Whitney from August 11 to August 13, 1960. Strikers not registering would be treated as having quit and not desiring to return to work. Those strikers who did register would then be recalled in accordance with the provisions in the Agreements. The operative paragraphs are set out in the margin. The Agreements provided for recall to occur in three phases, corresponding to paragraphs 4(a), 4(b) and 4(c). Under Phase 1, strikers would be returned to their prestrike jobs (i. e. same job code, department and shift) if they were available at the end of the strike. If a striker’s prestrike job was not available, under Phase 2 he would then be recalled to certain other jobs then available. Finally, under Phase 3 registered strikers not recalled up to that point would be put on a preferred hiring list and placed in jobs which developed before December 31, 1960, the expiration date of the Agreements, before new employees were hired. The order of recall under phases 2 and 3 was to be governed by the relative seniority of the strikers as provided in the collective bargaining agreements recently ratified by the Union membership as part of the strike settlement. Pursuant to the terms of the Agreements, a total of 6,536 strikers registered for reinstatement: 4,535 registered at Pratt & Whitney (4,515 at the East Hartford plant and 20 at the Manchester plant) and 2,021 at Hamilton Standard (1,721 at Windsor Locks and 300 at Broad Brook). From that point through the life of the Agreements, reinstatement proceeded generally as follows. At Pratt & Whitney 2,270 registered strikers returned to their identical prestrike jobs under Phase 1, and 793 returned to other jobs under the provisions governing Phase 2. Both of these steps had been substantially completed by early September 1960. The remaining strikers were notified that they had been placed on a preferred hiring list, and from this group 407 were recalled prior to the expiration of the Agreements. Thus, of a total of 4,535 registered strikers at Pratt & Whitney, 3,470 had been returned to work. Of the remaining 1,065 registered strikers, 223 had been removed from the preferred hiring list for other reasons (e. g. resignation), and therefore 842 strikers remained on the list and had not been hired by January 1. 119 of these individuals had been offered jobs and either refused the offer or failed to meet the physical requirements. At the Hamilton Standard plants as well, substantial numbers of strikers remained unrecalled when the Agreements expired. The Company recalled 758 strikers under Phase 1 and 104 under Phase 2. An additional 223 returned to jobs by being drawn off the preferred hiring list under Phase 3, leaving 941 strikers who had not been recalled pursuant to the Agreements. Taking account of resignations, etc., 843 remained on the preferred hiring list, 4 of whom had been offered jobs but who had declined to accept. In total, therefore, 1,562 (723 plus 839) employees desiring to return to work out of more than 6,500 registered strikers failed to receive offers of reinstatement under the Agreements. Some of these employees (278 at Pratt & Whitney and 177 at Hamilton Standard) were hired by the Company, during the first few months of 1961, but their status was then that of new employees, and they had lost accrued seniority and its attendant benefits. From the Union’s standpoint, this level of reinstatement was wholly unsatisfactory, and it is these figures which formed the motivation for the charge that the Company’s procedures breached the recall Agreements. According to the Union, the Company employed a variety of tactics designed to minimize the number of jobs available to registered strikers. Chief among these alleged artifices was a plan to depress the complement at the plants until after the Agreements had expired. Included as well were promotions and transfers of active employees to vacancies in preference to reinstatement of strikers awaiting recall. As noted, the district court rejected nearly all of the Union’s contentions. It is important to recognize that the aggregate figures set out above provide a broad and somewhat oversimplified picture of the recall process. The plants involved were not simple units in which all jobs were completely interchangeable. For administrative purposes plants were divided into separate seniority groups known as “seniority areas,” and an employee’s seniority (length of continuous service with the company) operated only within his seniority area. At Pratt & Whitney types of job skills were classified into “occupational groups.” Hamilton Standard collective bargaining contracts did not utilize the term “occupational group” but substituted the concept of “demonstrated ability” (previous experience in a job that had shown his ability in it). The recall Agreements incorporated this organizational structure, and limited the recall rights of strikers to available jobs and jobs which developed “in their occupational groups and seniority areas” (at Pratt & Whitney) and to jobs in which they had “demonstrated ability” (at Hamilton Standard). Thus, the mere existence of a job vacancy at one of the plants did not automatically mean that a striker had a right to fill the job. If, for example, the vacancy occurred in a seniority area and occupational group for which no strikers were awaiting recall, the Company was entitled under the terms of the Agreements to hire new employees, and in fact this did occur. At this point it is appropriate to consider the standard of review that governs our disposition of this appeal. This was a non-jury contracts case, albeit an exceptionally complicated one made more complex by the necessity of interpreting the contract with a view toward “the policy of our national labor laws.” Textile Workers v. Lincoln Mills, 353 U.S. 448, 456, 77 S.Ct. 912, 918, 1 L.Ed.2d 972 (1957). Under Rule 52(a) of the Federal Rules of Civil Procedure, we are bound by the factual findings of the district judge unless they are clearly erroneous. And although the district court’s interpretation of the contract involves a question of law and is fully reviewable, to the extent that the interpretation depends upon extrinsic facts, we are bound by the findings of the lower court with respect to such facts. See generally C. Wright & A. Miller, 9 Federal Practice and Procedure § 2588 at 750-51 (1971). Besides contending that some of the district court’s findings are clearly erroneous, at various points throughout its main brief the Union cites failures of the district court to make specified findings. But it must be remembered that the measure of the district court’s duty is not the contentions of the parties. One function of findings of fact is to aid the reviewing court. Russo v. Central School Dist. No. 1, 469 F.2d 623, 628 (2d Cir. 1972), cert. denied, 411 U.S. 932, 93 S.Ct. 1899, 36 L.Ed.2d 391 (1973). And if they are sufficiently comprehensive to disclose the steps by which the trial court reached its ultimate conclusion on the factual issues, the findings are adequate. C. Wright & A. Miller, supra, § 2579. In this case, perusal of the voluminous record coupled with a glance at the lengthy opinion of the district court reveals the diligence of the district judge and the detailed nature of his findings. That he may have failed to make each and every finding that the parties may deem pertinent is in itself no sign of error. B. Complement Depression It is an irrefutable fact that during the life of the recall Agreements the total work complement at all Company plants except Manchester (having a total pre-strike complement of only 133 employees) remained significantly below pre-strike levels. Furthermore, there is no question that starting almost immediately after the expiration of the agreements on December 31, 1960, the Company hired significant numbers of new employees, thereby bringing complements up to pre-strike size within several months. The Union contends that the Company deliberately kept the complements at artificially low levels. This alleged tactic, it claims, had the effect of denying reinstatement to some of the strikers, thereby reducing overall labor costs when the Company hired new (and lower paid) employees after January 1, 1961. The district court addressed much of its opinion to the issue of complement depression, concluding that: [T]he plaintiffs have failed to prove their allegations that the defendant, or either of its subsidiaries, deliberately and in bad faith depressed the bargaining unit during the life of the Settlement Agreements through December 31, 1960 or that it failed to exercise good faith in the performance of the Strike Settlement Agreements to avoid its contractual obligations. While the plaintiffs placed this question in issue by a prima facie showing, the defendant assumed its burden of going forward and advanced proof which satisfied the Court, that it had acted in good faith and was motivated by legitimate and substantial business justification in the performance of its obligations under the Strike Settlement Agreements. 299 F.Supp. at 912 (footnote omitted). The Union takes issue with these findings and contends, in addition, that even if the Company did not administer the Agreements in bad faith it was nevertheless obligated by the Agreements to restore the complements to pre-strike size. We consider first the nature of the Company’s obligations under the contract. 1. Restoration of Full Complements The district court did not expressly decide whether embodied in the Settlement Agreements was a commitment that the prestrike complements would be restored, but its opinion acknowledged the issue and by implication rejected the contention. See 299 F.Supp. at 897. The gist of the Union’s argument is that the terms “available” jobs and job openings “which develop” referred respectively to jobs that were not filled by replacements at the end of the strike and to jobs that were occupied at the end of the strike but subsequently vacated by employee terminations. In essence, the contention is that these definitions precluded temporarily reduced complements as a basis for denying jobs to strikers. At least beyond the first few weeks of the settlement, according to the Union, the Agreements took no account of strike dislocations and potential difficulties in the resumption of full production. The principal basis for this position is the presettlement negotiations between officials of the Company and representatives of the Union. Throughout the talks the Union remained acutely aware of the Company’s continuing program of hiring replacements. A principal area of discussion was the number of strikers who would not be reinstated, and Union negotiators requested Martin F. Burke, United Aircraft’s Vice President for Industrial Relations, to venture estimates on the number of strikers who would not be returned to work. Burke guessed that between 400 and 500 strikers at Hamilton Standard would have no jobs at the expiration of the strike. At Pratt & Whitney, Burke estimated that the number would be larger. These estimates were admittedly based on the assumption that the plants would again operate at pre-strike complements. But it does not follow that because the number of replacements was of utmost concern to the Union and the existence of replacements was often discussed as the reason why strikers would not be reinstated, that the Agreements cast aside all business considerations. Indeed, such a construction would be extraordinary since it would require an employer to operate without regard to the necessity of gearing employee levels to output requirements or efficiency. And in fact there are indications in the record that the production requirements of the Company would be a factor in determining the level of striker reinstatement. In discussing the proposed terms of the recall Agreements with International Union President Hayes, Burke explained that the “filling out of any complement that [the Company] needed” would be from the preferred hiring list. At another point, Burke told Hayes that it was the Company’s intention to reinstate strikers “as quickly as possible, and take into account the production problem.” Thus, strike-related production problems were expressly within the contemplation of the parties, although they could not foresee the extent and duration of the reduced complements. In fact, the Union acknowledges as much but seeks to avoid undermining its interpretation of the Agreements by asserting that “[a]t no time did Burke indicate that ‘the production problem’ would take more than ‘a few weeks’ to solve . . . .” But this does not diminish the fact that the Agreements were made under the assumption that business considerations might prevent reinstatement of some strikers, albeit temporarily. That is to say, their jobs would not be “available” within the meaning of the Agreements. That there was not full discussion of temporary cutbacks in employment levels at the plants hardly seems surprising. There were no. plans permanently to abolish jobs, and resuming full production as quickly as possible would seem to benefit both the Union and the Company. Thus, their interests would normally not diverge on this point, and post-strike production levels would understandably not be a focal point in negotiations. Accordingly, we must reject the contention that the Agreements contained an implied obligation to restore full complements. And contrary to the assertions of the Union, this interpretation neither leaves the reinstatement rights of strikers to the untrammeled discretion of the Company nor is inconsistent with national labor policy. The Company was required to exercise good faith in its performance under the Agreements. It could not at its whim keep the complement below pre-strike levels; nor could it do so in order to discriminate against strikers. Rather, the Company could refuse to reinstate strikers only for legitimate and substantial business reasons unrelated to labor relations. See NLRB v. Fleetwood Trailer Co., Inc., 389 U.S. 375, 88 S.Ct. 543, 19 L.Ed.2d 614 (1967). We turn now to consider whether the district court was correct in concluding that the Company’s maintenance of the complements at reduced size met these criteria. 2. The Administration of the Agreements As noted above, after considering “the totality of the circumstances”, the district court found that the Company had not in bad faith depressed the complements during the life of the Agreements. Although the court acknowledged that the Union had made out a prima facie case of bad faith, the Company successfully rebutted this showing, satisfying the court that it had been motivated by legitimate and substantial business considerations. 299 F.Supp. at 912. The Union now attacks that finding as clearly erroneous. It assails the failure of the district court to make express findings on subsidiary matters deemed by the Union to be crucial; and. where the court did detail such findings, the Union contends that its determination is contradicted by other and more believable evidence that the court supposedly ignored. As demonstrated in the following discussion, we cannot agree that the district court was in error. At both Hamilton Standard and Pratt & Whitney the district court found that strike-caused production imbalances, consisting mainly of parts shortage bottlenecks, were the principal reason for reduced employee complements. The Union contends that this finding cannot stand. It relies heavily on the minutes of the August, September, and October 1960 meetings of the respective Operating Committees of Hamilton Standard and Pratt & Whitney as showing the existence of a “plan” to keep complements depressed until after the expiration of Agreements. The existence of such a plan, the Union contends, is inconsistent with any explanation based on parts shortages. The district court found little significance in the minutes, see 299 F.Supp. at 908, and we wholly concur in this assessment. A study of the minutes shows that they cannot reasonably support the Union’s theory of a plan to depress the complements, much less one conceived in bad faith as a retaliatory measure against the registered strikers. For example, at Pratt & Whitney, Mr. L. C. Mallett, the Chairman of the Operating Committee, admonished department heads to keep expenses at a minimum in order to remain within operating budgets. Mallett’s comments appear to reflect nothing more than a generalized corporate concern over minimizing costs and thus insuring profitability. Moreover, there is no indication that his remarks were aimed specifically at the East Hartford plant, the only one where complements remained below pre-strike levels, but rather were directed at all units within the division. Such discussions, as the minutes reveal took place, concerned the reinstatement of strikers and were nothing more than forecasts of the number of strikers who would be recalled to work in light of the projected manpower needs of the plants. On August 15, 1960, for example, N. B. Morse, personnel manager at Pratt & Whitney, reported that approximately 3,000 of 4,500 registered strikers were back at work and that it was expected that 300-400 more would be recalled before the end of the year. About a month later, Morse again reported that there would most probably be no openings before the end of the year for the approximately 1,200 registered strikers. The Hamilton Standard minutes, although slightly more suggestive, also cannot support an inference of bad faith. The minutes of the August 23,1960, meeting reveal that “[pjroduction workers totaled 1,750 pri- or to the strike and the factory intends to hold employment to 1,600 on a 3-shift operation to avoid a 1961 layoff. This will require 20% overtime during 1960.” However, the context of the statement reveals that the employment level was dictated by strike-related business disruptions and a parts inventory imbalance. To the extent that this might be considered a “plan” to depress the complement rather than simply a projection of manpower needs, it was one based on business eonsiderations and thus cannot be considered violative of the Agreement. It is clear that there existed no overriding concern with the extent of striker reinstatement; employment levels were not the tail that wagged the dog. Rather, projections were based upon anticipated business conditions. In contrast to the allegations of the Union, the Operating Minutes are actually supportive of the Company’s position that business exigencies kept complements below pre-strike levels. The minutes of the September 19, 1960, meeting at Pratt & Whitney show that the post-strike efficiency of the machine shop at the East Hartford plant was poor, resulting in a “disappointing” level of parts deliveries. The Hamilton Standard minutes for the October 18, 1960, meeting also refer to a “parts deficiency” occurring as a direct consequence of the strike. These were in fact the principal grounds for the district court’s conclusion that the Company acted in good faith throughout the recall period. Although reliance on the Operating Committee minutes is misplaced, the Union does not limit itself to that argument. It contends that quite apart from the existence of any plan, the parts shortage explanation does not hold up under scrutiny. It cannot account for either the pattern of employment during the period of the Agreements — complements at both divisions rather than gradually growing peaked at about Labor Day and thereafter continuously declined (at Hamilton Standard) or at least failed to regain that level before December 31, 1960 (at Pratt & Whitney) — or for the hiring surge that occurred after January 1, 1961. At this point a brief summary of the principal evidence relied on by the district court is required. To maintain some level of production during the strike, Hamilton Standard subcontracted some 265,000 man-hours of work to 22 different firms. In this connection, it also loaned out to the subcontractors the equipment and machinery necessary to accomplish this work. These contracts could not be cancelled immediately upon conclusion of the strike without subjecting the Company to liability for breach of contract. Furthermore, Hamilton Standard could not accept only partially completed goods without releasing the subcontractor from responsibility for defects. These circumstances led to an unbalanced flow of materials that inhibited the return to normal production. Witnesses from Hamilton Standard testified that for this and other reasons there was considerable disruption in the shop; some parts were in short supply, and others were not. The complexities of the situation were such that the production controls systems were unable to cope with them. To combat these difficulties, stop-gap measures were employed that were perhaps detrimental from the long range standpoint of getting back to normal operations but nevertheless served the immediate need of eliminating production bottlenecks. Overtime was utilized where it would be most efficient to continue production with workers already familiar with the particular processes involved and it was anticipated that the need would be temporary in nature. Besides testifying about Hamilton Standard’s production problems, these witnesses denied knowledge either of the existence of a plan to avoid hiring employees until after December 31, 1960, or of a policy of utilizing overtime as a substitute for additional manpower where the need was expected to be permanent. In large part the issue boiled down to a matter of credibility, and the district court could not have helped but be fully aware of the Union’s allegations of bad faith and the motivation for Company representatives to distort the truth. But the court apparently credited this testimony, and on the record before us, we are not inclined to upset that finding. Although the Union points to testimony from Company witnesses indicating that parts problems improved progressively throughout the Agreement period, and assert that this admission is inconsistent with the declining complement during the same period, we are not convinced that the contrast exposes a fallacy in the parts shortage explanation. A progressively improving situation would not immediately translate itself into a greater need for employees. Solution of difficulties in a single limited area, although contributing to an overall solution of production problems, would by itself add little of significance. That a single part is added to a fuel control for example, would put that device a step closer to completion, but it still would not make the control ready for testing or shipping. Furthermore, there is ample evidence in the record to support the district court’s conclusion that the increased hiring at Hamilton Standard in early 1961 was prompted by business considerations and was not merely the result of the expiration of the Agreement and the concurrent abolition of the preferred hiring list. Hamilton Standard first publicly indicated the existence of job openings for about 400 skilled machinists and technicians in a press release on January 6, 1961. On the previous day it had also sent letters to registered strikers who had not been recalled inviting them to apply for the openings. Although the speed with which these announcements followed the expiration of the Agreements makes Hamilton Standard’s motives suspect, there were other reasons behind the hiring. On December 21, 1960, Hamilton had received a pilot order for full controls for the Pratt & Whitney engines powering the Boeing 727. Although the order initially involved only 6-8 controls, development of such a control requires a great deal of skilled work. It was also hoped that the initial pilot order would lead to more sales, making the initial development phases worthwhile. Hamilton was also in the beginning phases of production and experiencing pressure to get moving on other equipment including a JFC26 control for a General Electric engine, and a complex highly classified system for a Pratt & Whitney engine. These factors were all noted by the district court and evidently formed the basis for a conclusion that there were business reasons to undertake hiring of new employees in early 1961. Coupled with the Company’s explanation for the level of employment during the Agreement, they provide an adequate basis for the ultimate finding that complements at Hamilton Standard were not depressed in bad faith. At Pratt & Whitney the explanation for reduced employment levels was similar. During the strike, the Company sought to complete manufacture of engines that had been in the latter stages of production and to continue deliveries insofar as possible. This policy resulted in production line disruption and parts shortages as materials were pulled out of earlier stages in the production line and already-manufactured parts were utilized but not replaced. Thus, upon termination of the strike, return to normal production depended upon depleted supplies of parts becoming replenished. This responsibility fell upon the machine shop, the largest single section of the East Hartford plant and the section that had the task of manufacturing the parts used in the various stages of the assembly process. Without an adequate supply of all necessary parts, there would be a natural depression of the work force required in other sections of the plant. In short, the machine shop was the key to restoration of a full complement. Prior to the strike the machine shop employed 4,820 people; on December 31, 1960, it employed 4,909, an increase of 89. Moreover, most strikers registering for recall to the machine shop were in fact recalled (1,115 of 1,296). The Company stresses these statistics as showing that it was straining to obtain an adequate supply of parts. The Union, on the other hand, points out that after an initial restaffing resulting in a peak population about Labor Day, the Machine Shop population was actually allowed to decline until December when more employees were again added. This pattern, argues the Union, coupled with a marked increase in the machine shop through the first three months of 1961, forecloses the Company’s protestations that it was straining to resume full protection. The trial judge did not draw the inference of bad faith advanced by the Union. He concluded that it was not likely that the Company would repopulate the machine shop, recalling most strikers assigned to that area, if it was simultaneously embarked on a program of complement depression. See 299 F.Supp. at 910. The Union’s theory depends upon acceptance of the idea that the Company developed an elaborate charade to obtain an ample — but not too ample — level of production. It also ignores the fact that there may have been difficulties regaining normalcy in a section after a bitter and protracted strike, as the Operating Committee minutes reveal were present at the East Hartford Machine Shop. That the district court rejected this scenario was within its proper role as trier of fact. The Union also complains that the trial judge made no finding which would explain the hiring of over 1,700 employees and restoration of a full complement at Pratt & Whitney during the first three months of 1961. There was testimony as to the business reasons therefor and specific findings on the subject were not indispensable. The ultimate question was whether the Company depressed the complement in bad faith during the course of the Agreements. The degree of hiring after January 1, 1961, was important only to the extent that it shed light on the motivation for Pratt & Whitney’s actions during the Agreements. The district court made a detailed review of the evidence in concluding that the complement at Pratt & Whitney had not been depressed. By implication in 1961 hirings were not the inevitable result of prior breaches of the Agreements. Under these circumstances, it was not imperative that the district court detail its findings with respect to this subsidiary matter. C. Transfers and Promotions Throughout all three phases of the Strike Settlement Agreements, the Company’s policy was to operate as if the unrecalled registered strikers had been laid off for lack of work. In previous layoff situations the Company had continued to make promotions and transfers among its active employees, and this practice continued also during the recall period. A significant number of these promotions and transfers were into jobs for which registered strikers were still awaiting recall, thereby foreclosing the striker’s opportunity to fill that vacancy. The Company’s position ,was that this was an inevitable consequence of following long-established procedure. The Company’s policies were summarized in a memorandum dated September 8,1960, written by J. E. Vandervoort, personnel manager at Hamilton Standard. The memorandum purported to set out the “ground rules” for handling recall of registered strikers during the term of the Hamilton Standard Agreement. The “ground rules” can be summarized as follows: 1. When a job became available it would be offered first to the most senior active employee who had held the same job before the strike but had returned to a different job at the end. The Company saw the need to “make whole” active employees as its first obligation. 2. The Company would then consider filling the vacancy by transferring another qualified employee, although- this method was to be approached with caution. 3. If the job was still unfilled, Hamilton would look to the Preferred Hiring List for a qualified employee in the appropriate seniority area. 4. The Company would then look for a qualified employee from another seniority area who was on the Preferred Hiring List. 5. After these methods had been exhausted, Hamilton Standard would hire outside the Preferred Hiring List. The initial premise of the district court was that it was proper for the Company to administer the Agreements using layoff procedures. However, not all promotions and transfers during the recall period were of precisely the same character, and the court was presented with a myriad of different situations. Although in purely numerical terms it held that most promotions and transfers were proper, it found breaches of the Agreements in instances affecting some 72 registered strikers. The parties have not appealed all of the district court’s findings in this area. The Union challenges the district court’s resolution of two issues: that the transfer of junior active employees to jobs for which senior registered strikers were awaiting recall did not violate the Agreements; and that promotion and transfer of apprentices to bargaining unit jobs for which registered strikers were awaiting recall did not violate the Agreements. The Company appeals the finding that promotion of junior active employees other than apprentices into jobs for which senior registered strikers were awaiting recall constituted a breach. The Company has not appealed other aspects of the district court’s judgment concerning promotions and transfers, and of course, the judgment is conclusive with respect to those matters. The district court’s point of departure on the question of promotions and transfers was that the basic intent of the Agreements was to treat registered strikers as if they had been laid off. This was the position that had been advanced by the Company, although the point was vigorously disputed by the Union. Because we are unable to accept the district court’s initial premise, our view of the question is somewhat different. Neither however do we accept in its entirety the interpretation of the Agreements advocated by the Union. The district court based its conclusion that layoff policies should govern the recall of strikers both on the language of the Agreements themselves and on the provisions of the “interlocking” collective bargaining contracts. The latter contained broad “management rights” clauses, which reserved the Company’s right to determine when transfers and promotions should be made. Several factors persuade us, however, that the Strike Settlement Agreements restricted somewhat the freedom to promote and transfer that the Company might have enjoyed during a layoff. Perhaps the foremost consideration is that the situation at the conclusion of the strike was fundamentally different than a layoff. As the district court noted, during periods of layoff workers are bumped downward by more senior people whose jobs have been eliminated. See 299 F.Supp. at 917. The result, generally speaking, is that the more junior employees end up being the ones who are out of work. In contrast, employees still out at the end of the strike presumably ranged from among the most senior to the most junior. Nor does the language of the Strike Settlement Agreements dictate that layoff procedures regarding transfers and promotions should govern. Paragraph 4(a), for example, makes no mention of layoff, and at least initially, recall of strikers bore no relation to post-layoff recall procedures. During Phase 1 strikers were to be recalled to their old jobs, if they were available, without regard to seniority considerations that would govern after a layoff. Only in paragraphs 4(b) and 4(c) are there any indications that layoff considerations were a factor at all. But an examination of the layoff references demonstrates that they were intended only to fix the order of recall among the registered strikers themselves. The provisions of Article VII, Sections 1 and 2 (Section 1 of the Broad Brook contract) of the respective collective bargaining contracts, referenced in paragraphs 4(b) and 4(c) of the Agreements, are very limited in scope. The operative provisions in each of the contracts is Article VII, Section 1(a). Although the precise terminology differs slightly among the contracts so as to accommodate the varying administrative structures of the plants, the provision in the contract covering Hamilton Standard’s Windsor Locks plant is illustrative: In the case of an indefinite layoff for lack of work, employees shall be laid off from and recalled to specified seniority areas in accordance with their seniority (length of continuous service with the company since the most recent date of hire) and demonstrated ability. Plainly, the section deals only with the order of recall among those laid off and says nothing about promotions and transfers. In this respect, an omission from the provisions of the collective bargaining contracts expressly incorporated into the Strike Settlement Agreements is significant. Article VII of the respective collective bargaining agreements also contained a clause providing in part: Before new employees are hired in a given seniority area, the employees who are still laid off from that seniority area shall first be offered employment in that seniority area . ... The company will give consideration to transferring back to his former job and rate an employee who was transferred to a lower-rated job within his seniority area as a result of a readjustment of personnel arising from a layoff. Had the intention been to incorporate layoff transfer policies into the recall Agreements, it seems likely that the parties would have referenced the one provision expressly dealing with transfers during layoffs. Furthermore, although paragraph 4(b) of the Pratt & Whitney Agreement provides that “strikers will be treated as if they had been laid off,” the same language was deleted from the Hamilton Standard Agreements at the request of representatives from Lodge 743, and a provision stating that strikers would be recalled to “comparable” jobs inserted. The purpose of the change was to insure that it was clear that a striker had a right to return to his old job on a different shift, if it was available. 299 F.Supp. at 900. Presumably during recall from a general layoff there would be no such guarantee. That the Company readily agreed to this change in language negates any purported significance of the “as if they had been laid off” language in the Pratt & Whitney Agreement. Nor, finally, can the Strike Settlement Agreements be read as incorporating by reference all relevant provisions of the collective bargaining contracts negotiated concurrently with them. Had that been the desire of the contracting parties, they could have done so expressly. Instead they chose to cite only a specific portion of them. Under these circumstances it seems proper to apply the well-established rule that “a reference by the contracting parties to an extraneous writing for a particular purpose makes it part of their agreement only for the purpose specified.” Guerini Stone Co. v. P. J. Carlin Construction Co., 240 U.S. 264, 277, 36 S.Ct. 300, 306, 60 L.Ed. 636 (1916). But it does not follow that because the Company’s transfers and promotions cannot be justified on the ground that they were simply a continuation of a practice long followed during layoffs, they violated the Strike Settlement Agreements. Promotions and transfers are an integral part of any business operation, particularly a large manufacturing plant, and the Agreements were necessarily made against this backdrop. In fact, the Union admits that nothing prohibited the Company from making transfers and promotions during the recall period. It is only promotions and transfers that prevented the recall of strikers which the Unions claim violated the Agreements. The Agreements guaranteed that strikers would be recalled to “available” jobs and jobs “which develop.” To that extent, the Union argues, the Agreements limited the Company’s freedom of action. While we agree with the Union that the Agreements did act as a limitation upon the Company, we differ on the extent of that limitation. At trial, the Company claimed that transfers and promotions were necessary to contend with the imbalances caused by the strike. In other words, work might dry up in one particular area, but at the same time, openings would develop in another where registered strikers were perhaps awaiting recall. If the Agreements were construed as prohibiting promotions and transfers to fill those openings, the Company argued that it either would be faced with the necessity of laying off active employees while concurrently recalling strikers or would have more workers on its payroll than it could productively employ. The Union contends that the Agreements required the Company to recall the registered strikers under these circumstances and to make the layoffs if they were indeed necessary. We consider that interpretation of the Agreements to be unreasonable. The Company was not required to recall a striker where to do so would result in the layoff of an active employee. There is no reason why the consequences of the production imbalance caused by the strike should have been visited upon the active employees who were themselves exercising a section 7 right by refraining from collective activity. 29 U.S.C. § 157. The Company’s right to make promotions and transfers to deal with the problem of imbalance and keep its employees productively employed was embodied in the terms “available” jobs and jobs “which develop.” As we have seen, these terms carried the implication that strikers would not be recalled until their services could be productively employed. They permitted, in our view, the Company’s reshuffling of its productive resources so as to permit their most efficient utilization. No case insofar as we are aware, has required an employer to lay off its active employees so as to make room for strikers. And any such approach would be fundamentally inconsistent with an employer’s right to hire permanent replacements for strikers and retain the replacements after the strike while the strikers remain out of work. NLRB v. Mackay Radio & Telegraph Co., 304 U.S. 333, 58 S.Ct. 904, 82 L.Ed. 1381 (1938). On the other hand, where a promotion or transfer was made not to correct a production imbalance and the effect of the promotion or transfer was to deny recall to a striker or cause a striker to be recalled to a lower labor grade than he otherwise would have, the action constituted a breach of the Agreements because it denied an available job to a registered striker. Although we cannot on appeal determine the precise effect of this interpretation of the Agreements on the award of damages made by the district court, we can measure the effect in general terms. A more precise determination must be made on remand when the district court makes the findings hereinafter described. We consider first the lateral transfer or demotion of junior active employees to positions within the same seniority area for which senior registered strikers were awaiting recall. The district court found that such transfers did not breach the Agreements, and the Union has appealed this ruling. At Pratt & Whitney, recall under the Agreements was by seniority area and occupational group. Transfers made for the purpose of correcting a production imbalance and avoiding a layoff of an active employee were permissible under the Agreements, as we have indicated. However, even transfers made for other purposes would not have had the effect of denying reinstatement to a registered striker, since they would have necessarily had the concomitant effect of opening up positions within the same occupational group and seniority area which the registered strikers could fill. Accordingly, we can perceive no basis for concluding that transfers at Pratt & Whitney could have injured a registered striker in contravention of the Agreement. At Hamilton Standard the concept of “demonstrated ability” rather than “occupational group” was used to determine right of recall within a seniority area. Therefore, it is not inevitably true that a transfer within a seniority area, not made as a production adjustment to avoid a layoff, would open up a position for a registered striker. If at Hamilton Standard a junior active employee was transferred to a different position in preference to a senior registered striker who was awaiting recall to that position, and the striker had no “demonstrated ability” in the vacated position, the effect would have been to deny reinstatement to a registered striker. If such a transfer was not necessary to correct a production imbalance, it constituted a breach of the recall Agreement. As a practical matter, unless the Company was acting in bad faith with the specific purpose of denying reinstatement to registered strikers, something the district court found that the Company did not do, it seems unlikely that it would demote or laterally transfer employees where they could be used productively in their present positions. Consequently, in all probability, transfers at Hamilton Standard did not violate the Agreement as we have interpreted it. Nevertheless, on remand the Union should have an opportunity to demonstrate that some transfers were made for purposes other than to correct production imbalance, and where such a transfer blocked the recall of a senior registered striker to recover appropriate damages. With respect to the promotions of junior registered strikers, the district court found that 45 senior registered strikers (14 at Pratt & Whitney and 31 at Hamilton Standard), were entitled to damages, and the Company appealed this ruling. At Pratt & Whitney, essentially the same analysis applies as in the case of transfers. Promotions within the same seniority area and occupational group which were not made as a necessary production adjustment would, like transfers of the same sort, have opened up a position for a registered striker in the promotee’s vacated position. Thus, such a promotion would not have denied reinstatement to a registered striker altogether. However, unlike the case of transfers, some registered strikers may, as a result of these promotions been recalled to lower paying positions than those to which they would have been entitled absent the unauthorized promotion. Accordingly, the district court should determine which, if any, of the 14 blocking transfers at Pratt & Whitney were prompted by a need to adjust production and avoid layoffs. Any such promotions did not breach the recall Agreement. Likewise, at Hamilton Standard, the district court must determine which of the 31 promotions that denied reinstatement to registered strikers or caused them to be returned to lesser positions were caused by production needs and which were motivated by a desire to reward an employee for good performance or were for some other purpose not related to a necessary production adjustment. Only the latter type of promotion constituted a breach of the Agreement. A similar analysis governs promotions to apprentices to jobs for which registered strikers were awaiting recall. As found by the district court, promotion to a bargaining unit job was the culmination of a three-year contractual period of training during which the apprentice became certified in a particular skill. 299 F.Supp. at 923. The Union has appealed the ruling that these promotions did not violate the Agreements. The Company was not obligated to lay off the apprentice after the completion of his period of training on account of the unsettled production conditions created by the strike. Nor was it obligated both to promote the apprentice and recall a striker to the same position, resulting in a surplus of employees. Accordingly, we affirm the finding that promotions of apprentices did not breach the Agreements. Summarizing our holding with respect' to the issue of promotions and transfers of junior active employees, we find that lateral transfers, demotions, and promotions made for the purpose of correcting production imbalances and avoiding layoffs where work in a particular area ceased to be available did not constitute breaches of the Strike Settlement Agreements. Personnel adjustments made for other reasons that had the effect of blocking reinstatement altogether or causing a striker’s reinstatement to a lower position, on the other hand, did violate the Agreements. We have determined that no transfer or demotion made at Pratt & Whitney would have had the effect of depriving a registered striker of reinstatement, and therefore, the district court on remand need not consider transfers and promotions at Pratt & Whitney. At Hamilton Standard, however, we cannot say to a certainty that no blocking transfers were made for purposes other than to correct a production imbalance, and therefore it is open on remand for the Union to show that such transfers did occur and that they deprived a registered striker of reinstatement. With regard to the 45 promotions found by the district court to have breached the Agreement, the district court should inquire into the reasons for these promotions. If they were made simply as a matter of personnel policy and not as a production adjustment, then the promotions were indeed breaches of the Agreements, as the district court found. If, on the other hand, the promotions were necessary production adjustments caused by post-strike production conditions, these promotions did not violate the Agreements. The district court’s determination with respect to apprentices is affirmed. D. Preference for Non-striker Absentees There were a significant number of non-strikers who nevertheless remained absent during the course of the strike (the absence having commenced either before or during the strike) because of illness, fear of violence, or other personal reason. All of these individuals desiring continued employment with the Company were immediately reinstated at the conclusion of the strike. The district court found that this practice did not violate the Agreements, since during non-strike periods the Company would have regarded the reasons given as justifying an absence. 299 F.Supp. at 897. The district court also found no evidence that the Company had used this procedure as a means of discriminating against particular strikers. We agree with the conclusion of the district court. The Strike Settlement Agreements were silent on the issue of non-striker reinstatement, and an inference that non-strikers were by implication subject to its terms is unwarranted. The jobs of economic strikers were subject to being lost either because permanent replacements were hired or for other legitimate and substantial business justification. The Union and the striking employees were well aware of this risk. In contrast, there is no indication that those absent for valid personal reasons during non-strike periods risked losing their jobs. It would have been manifestly unjust to expose them to the same risks as strikers merely because of the fortuity that the cause of their absence occurred during a strike. Indeed, we do not believe that strikers would reasonably have expected that these non-strikers would be treated in the same manner with respect to reinstatement. The same can be said for those employees who were absent during the strike out of a bona fide fear of violence. These individuals did not voluntarily encounter a risk of loss of their jobs, and it would be unfair to treat them identically with those who did. Interpreting the Agreements as not controlling the reinstatement of non-striker absentees is not, in our view, inconsistent with cases holding that an employer may not discriminate between strikers and non-strikers in declaring eligibility for certain benefits. NLRB v. Great Dane Trailers, Inc., 388 U.S. 26, 87 S.Ct. 1792, 18 L.Ed.2d 1027 (1967); NLRB v. Frick Co., 397 F.2d 956 (3d Cir. 1968). While strikers have a right to expect that engaging in protected collective activity will not subject them to discriminatory treatment with respect to benefits, reinstatement must stand on a different ground for the reason that in leaving their positions vacant, strikers knowingly take the risk that their position will not be available at the strike’s conclusion. E. Prejudgment Interest Although our analysis of the Strike Settlement Agreements requires reconsideration of the amount of damages, we take up the issue of prejudgment interest for the district court’s future guidance. Final judgment in this case was dated June 16, 1972. The district court awarded prejudgment interest on the recoverable damages from March 20, 1969, the date of the filing of its principal opinion containing its findings of fact and conclusions of law. The court chose that date because that was when the damages could be “ascertained as a liquidated sum.” Lodge 743, International Ass’n of Machinists v. United Aircraft Corp., 336 F.Supp. 811, 815 (D.Conn.1971). The Union contends that interest should have been awarded from the dates of the violations of the contract. They point to the policy of the National Labor Relations Board to award interest on its backpay awards and argue that the same remedy should apply in Section 301 suits for violations of labor contracts. This conclusion, it is urged, follows from the decision in Textile Workers v. Lincoln Mills, 353 U.S. 448, 456, 77 S.Ct. 912, 1 L.Ed.2d 972 (1957), holding that courts are to apply federal law in section 301 suits, looking to the policies behind our national labor laws in order to fashion appropriate rules. For the same reasons the Union argues that the district court should follow the NLRB practice of computing back pay on a quarterly basis, rather than make a single computation covering the entire period of unemployment. We of course agree that the decision whether to award prejudgment interest is governed by federal law, although it may be proper, as a matter of convenience, to look to state law in order to determine the appropriate rate. But from this premise does not flow the conclusion that remedies adopted by the NLRB are to be mechanically adopted by the courts in section 301 actions. Whether to award prejudgment interest in cases arising under federal law has in the absence of a statutory directive been placed in the sound discretion of the district courts. Blau v. Lehman, 368 U.S. 403, 414, 82 S.Ct. 451, 7 L.Ed.2d 403 (1962); Chris-Craft Industries, Inc. v. Piper Aircraft Corp., 516 F.2d 172, 190-91 (2d Cir. 1975); Occidental Life Ins. Co. of North Carolina v. Pat Ryan & Associates, Inc., 496 F.2d 1255, 1268-69 (4th Cir.), cert. denied, 419 U.S. 1023, 95 S.Ct. 499, 42 L.Ed.2d 297 (1974) (securities laws); Wolf v. Frank, 477 F.2d 467, 479 (5th Cir.), cert. denied, 414 U.S. 975, 94 S.Ct. 287, 38 L.Ed.2d 218 (1973) (securities laws); Wessel v. Buhler, 437 F.2d 279, 284 (9th Cir. 1971)