DONALD RUSSELL, Circuit Judge:
This is a consolidated appeal involving three actions charging unconstitutional overcrowding in three separate units of the Maryland State Prison System. These actions have been engaging the attention of the Maryland District Court for a number of years. One relates to conditions at the Maryland House of Correction (“MHC”) and resulted in a decree reported under the title Johnson v. Levine, 450 F.Supp. 648 (D.Md.1978). A second, reported in Nelson v. Collins, 455 F.Supp. 727 (D.Md.1978), dealt with conditions at the Maryland Penitentiary and the Maryland Reception, Diagnostic & Classification Center (generally referred to as “MRDCC”). In both of those cases the District Court found unconstitutional overcrowding and ordered by way of relief the elimination of double celling on or before April 1, 1979. From both of those decrees, an appeal was taken to this Court. After an expedited consolidated en banc hearing, the appeals were decided in our opinion reported under the title, Johnson v. Levine in 588 F.2d 1378 (4th Cir. 1978).
In our opinion in Johnson, we began by declaring that “double celling,” the housing of two prisoners in a cell initially designed for single occupancy, was not itself a “violation of the Constitution,” but added that, if accompanied by other serious deprivations, it could be “a relevant factor” in determining whether “[u]nder the totality of all the circumstances [including the double celling] the aggregate effect amounts to cruel and unusual punishment.” On the facts of the two cases under review, we held that the District Court had “reasonably found that the point [of cruel and unusual punishment in the constitutional sense] had been reached here.” But we added in connection with the remedy decreed by the District Court, particularly the time fixed for the correction of the overcrowding (i. e., April 1, 1979), that
“. . . we are convinced that the overcrowded conditions cannot be completely eliminated without the construction and utilization of a new facility, which Maryland proposes to have available by June 1, 1980. Since the constitutional violation here is not as extreme or as shocking as in some of the reported cases, and since Maryland’s plan is practical and reasonable and will achieve the required objective of elimination of overcrowding in its penal institutions, we think its plan and its schedule deserve judicial approval.” Id. at 1381.
We accordingly remanded the cases to the District Court “with instructions to fashion new decrees which [would] incorporate Maryland’s plan and its schedule [of June 1, 1980] for the elimination of overcrowding in the two penal institutions.”
On remand, the District Court entered modified decrees in accordance with our mandate. In the Johnson case (MHC), the modified decree required the elimination of double bunking by June 1, 1980 and added “that on and after that date, no more than 1294 inmates could be housed at the MHC.” Similarly, in the Nelson case (MRDCC), double celling, “with limited exceptions,” was ordered eliminated “by June 1, 1980, and that thereafter the population of the combined institutions should not exceed 1003 inmates.”
During the same time that the actions involving the Maryland House of Corrections (Johnson v. Levine) and the Penitentiary Complex (Nelson v. Collins) were pending, a third action was begun by the inmates at the Maryland Correctional Institution at Hagerstown (MCI). The constitutional claims in this case were similar to those in the other two actions. That action resulted in a consent decree entered on the same day that we heard the appeals in Johnson and Nelson. Under this consent [422]*422decree the defendants (the Governor, the Commissioner of the State Division of Correction and the Institution Superintendent) agreed to a schedule whereby double celling at the Institution would be eliminated by January 1, 1981, after which time the Institution’s inmate population would be limited to no “more than six hundred seventeen (617) inmates.” Washington v. Keller, 479 F.Supp. 569 (D.Md.1979).
Since the entry of the decrees in the three cases, the record indicates that the State authorities have proceeded with reasonable diligence to meet the mandates of the Court. So much was found by the District Court in its order of January 5, 1981, to which we refer in greater detail later. Recognizing, as we had in our opinion in Johnson, that the elimination of the unconstitutional conditions in the State prison system depended largely upon “the construction and utilization of a new facility,” the State has contracted for additional facilities designed to relieve those conditions.1 However, the State authorities have encountered a number of unexpected delays in the completion of these new facilities. This had delayed compliance with the Court Decrees within the time limits fixed therein. The District Court did not find, however, that these delays were the result of “deliberate” ignoring of the Court’s decree or that the defendants had not made “good faith efforts * * * to meet the requirements of the Decree.” Accordingly, because of the “good faith” efforts of the defendants to meet the deadlines fixed in the Decrees, various extensions have been requested by the State officials for compliance with the Court decrees and were granted on most occasions.
Despite the continued construction delays experienced, the prison officials had by October 1, 1980, achieved through various expedients full compliance with the Court’s mandates to eliminate double celling at both the MHC and the MRDCC institutions. Beginning in October, 1980, and continuing thereafter, however, the prison authorities were confronted with a large influx of additional prisoners. This increase in the prison population was due to a number of factors beyond the control of the prison authorities. As a result, the prison officials were forced to exceed the provisions of the Court’s decrees for prison population at the two facilities. At this point the plaintiffs petitioned the District Court to find the defendants in contempt in the Johnson and Nelson cases. The defendants, in turn, sought an extension of time for compliance with the Court’s mandates. The petition for a finding of contempt was denied in a decree dated January 5, 1981. In so doing the District Court said:
“Certainly, defendants have been energetic, particularly in recent days, in searching for ways to solve the overcrowding problems which continue to exist at state penal institutions. It is not as apparent that defendants have acted as promptly or as effectively as they reasonably could have to eliminate unconstitutional overcrowding at the MRDCC. However, the test is reasonable diligence, and in view of the many unforeseen setbacks encountered by defendants in recent months, this Court is satisfied that they have met the required standard.”
But, in denying any citation of civil contempt on the plaintiffs’ motion, the District Court in its order of January 14, 1981, refused to extend the date for compliance by the defendants from October 1, 1980 to August 1, 1981, as requested by the defendants and provided rather for a monthly monitoring by the Court of the progress of the defendants in meeting the requirements of the Decrees at the prison facilities. It provided instead in its Decree, that “[u]ntil the proposed new prison facilities are ready to receive prisoners, a hearing will be held in open court every 30 days.” It concluded with a requirement “that the [State] Parole Commission adopt some of the suggestions [423]*423made in this ease for accelerating releases on parole.”2
On April 24, 1981, the defendants submitted a revised plan under which, the defendants, in order to relieve overcrowding at the MHC and MRDCC institutions, would double cell, under certain conditions, at the new and modern Jessup Annex, in process of completion, and would double bunk some persons in the open dormitories at the MHC in order largely to meet “the cyclical overflow [of] inmates either backed up at local jails or excess population from the Reception Center.”3 The District Court denied both the request of the defendants for approval of their plan to relieve overcrowding by double celling at the new Jessup Annex and double bunking at the MHC and, also, refused to extend the time for compliance by the defendants. Almost simultaneously, by Order dated April 27, 1981, the District Court required the Parole Commission to parole “approximately fifty state prisoners to their federal de-, tainers for service of federal sentences previously imposed” and the defendant prison officials to “transfer approximately fifty state prisoners who voluntarily agree to be transferred to the United States Bureau of Prisons in accordance with state and federal compacts.” From both of these orders the defendants appealed.
Along with these proceedings involving MHC and MRDCC, the defendants in the proceeding involving MCI-H requested an extension of time for compliance with the Consent Decree in that case to August 1, 1981, when, upon completion,,,of the new Jessup Annex and the new Reception Center, it was expected that compliance at MCI-H could be achieved through double celling of transferees at the Jessup Annex. The District Court granted this request but limited the time for compliance to April 15, 1981. The defendants were prevented from meeting that deadline because of unavoidable delays in the completion of the Jessup Annex and the Reception Center. The District Court found the defendants in contempt and levied civil sanctions against them despite the delays in completion of the Jessup Annex and the Reception Center. From this order, too, the defendants appeal.
Since all three of the cases, consolidated in two actions, involve a single state-wide prison system, in which what is done at one institution interacts on the other institutions in the system, we consolidated the cases for appeal and now reverse in part and affirm in part the decrees in the cases:
The issues presented on appeal are:
(1) Did the District Court err in ruling that double celling at the Jessup Annex was unconstitutional and represented an invalid method of relieving overcrowding at the three prisons involved?
(2) Was the District Court in error in refusing to permit double bunking in certain of the dormitories in MHC?
(3) Did the District Court err in ordering the transfer of fifty inmates at MHC and MRDCC to federal prisons in its order of April 27, 1981?
Before dealing directly with the primary issues in controversy, it is necessary to take note of a preliminary contention of the plaintiffs. It is their position that the previous decrees of the District Court prohibited double celling and double bunking and such ruling is res judicata, subject only to modification or vacation if “circumstances [are] so changed that ‘dangers once substantial, have become attenuated to a shadow’ ” and if, as a result of such new and unforeseen circumstances, “grievous wrong” will result from a refusal to modify or vacate the injunction. For this position, they rely on United States v. Swift & Co., 286 U.S. 106, 52 S.Ct. 460, 76 L.Ed. 999 (1932). In Swift, the Court did state the circumstances under which a court may modify its previous decree, but, in so doing, it made a sharp distinction between two [424]*424types of decrees. The first it described as the “continuing decree . . . directed to events to come . . . [involving] the supervision of changing conduct or conditions and are thus provisional and tentative;” the second it identified as the injunction granted to protect rights “fully accrued upon facts so nearly permanent as to be substantially impervious to change.”4 In the first case, modification under appropriate circumstances is clearly permissible; in the second the strict standard relied on by the plaintiffs is applied.5 A familiar example of the first type is provided by Philadelphia Welfare Rights Org’n. v. Shapp, 602 F.2d 1114, 1121 (3d Cir. 1979), in which the Court said modification was proper where “Respite a good faith effort at compliance, circumstances largely beyond the defendants’ control and not contemplated by the court or the parties . . . [when the injunction was granted] put achievement of the . . . timetable [as fixed in the injunction] beyond reach.”6 The question for purposes of decision here becomes, therefore, whether there have been, since the entry of the original Decree in these cases, changes either in operative facts or laws which cast a new light upon the facts or law as originally ruled on in these cases. Unquestionably, the Decrees involved here were in the very class described in Swift, in which the terms of the injunction were “provisional and tentative” subject to “changing conduct or conditions.” Nor have we any difficulty in finding that there have been such changes both in law and in operative facts in these cases.
Since the entry of the Decrees in these cases there has been considerable clarification in two recent Supreme Court decisions of the constitutional implications in the state prison context of the “cruel and unusual punishment” provision of the Eighth Amendment, the question which lies at the heart of the issues in these appeals. The first of these decisions — Bell v. Wolfish, 441 U.S. 520, 99 S.Ct. 1861, 60 L.Ed.2d 447 (1979) — involved, among other things, double bunking, primarily of pretrial detainees, though convicted prisoners were also involved, in a Correctional Center in New York City. This is the very question posed by the defendants’ request to double bunk prisoners in the dormitories in MRDCC. The cells in the New York City prison facility were designed for single occupancy and the planned capacity .of the facility was fixed. However, persons committed to pretrial detention began to increase at an “ ‘unprecedented’ ” rate. To meet this increase, the prison officials inaugurated double bunking at the facility and, on occasions, the increase became so great they assigned inmates “to sleep on cots in the common areas until they could be transferred to residential rooms as space became available.” A class action was begun challenging this and many other conditions at the prison facility as applied basically to detainees.
[425]*425The District Court and the Court of Appeals in Bell enjoined, inter alia, the practice of double bunking and the temporary use of cots in the common areas. In reviewing those decisions, the Supreme Court began by marking out the distinction in rights between a detainee and a convicted prisoner. The rights of the detainee are governed by the Due Process Clause, which “requires that [he] not be punished,” whereas “[a] sentenced inmate, on the other hand, may be punished, although that punishment may not be ‘cruel and unusual’ under the Eighth Amendment.” 441 U.S. at 535, n. 16, 99 S.Ct. at 1872, n.16. There seems to have been no dispute that double bunking was not “punishment,” a finding that would have established that the subjection of the convicted inmates to double bunking would not have been within the interdict of the Eighth Amendment.7 What the District Court and the Court of Appeals had rested their decisions, enjoining the double bunking of detainees, on was that as unconvicted persons having Due Process rights (which implicitly the Supreme Court assumed to be greater than those of the convicted prisoner whose only protection was against “punishment”) the detainees could not be subjected to double bunking in the absence of compelling necessity. This test was rejected in favor of a reasonable standard. The Court then reviewed under this reasonable standard the various contentions pressed by the plaintiffs in their objections to double bunking. The first was “that the rooms were designed to house only one inmate.” A second was that the confinement of two persons in one cell “constituted a ‘fundamental deniaO] of decency, privacy, personal security, and, simply, civilized humanity . . .. ” The decision dismissed as without merit both of these contentions.8 It, also, took note of the contention of the plaintiffs that the prison officials could, by some adjustment or changes, avoid double bunking and that, therefore, double bunking was “unreasonable.” This claim was found without merit, the Court declaring that “[gjovernmental action does not have to be the only alternative or even the best alternative for it to be reasonable, to say nothing of constitutional.”9 It added that “[t]he court might disagree with the choice of means to effectuate those interests, but it should not ‘second-guess the expert administrators on matters on which they are better informed .... Concern with minutiae of prison administration can only detract the court from detached consideration of the one overriding question presented to it: does the practice or condition violate the Constitution?’ ”10 The Court went on to emphasize that the opinions and recommendations on prison standards by various groups “may be instructive in certain cases, [but] they simply do not establish the constitutional minima; rather, they establish goals recommended by the organization in question.”11 It ended the discussion by holding that double bunking of detainees in the facility was not unconstitutional, even though the double bunking “may have taxed some of the equipment or particular facilities in certain of the common areas.”12
After argument before this Court on these appeals by the parties, the Supreme Court buttressed its decision in Bell with Rhodes v. Chapman, - U.S. -, 101 S.Ct. 2392, 69 L.Ed.2d 59, (1981). In that case the Ohio prison officials, fáced with a great increase in its prison population, sought, as has the State of Maryland in these cases, to relieve the problem by double celling prisoners in its Southern Ohio Correctional Facility (SOCF), constructed in the early 70’s. The cells in SOCF, it was [426]*426noted, were “designed, built and rated to house one man.” As a result of the double celling at the facility, the prison population there was increased by 38% over its “design capacity.” The prisoners in SOCF filed suit, claiming that double celling in SOCF under these circumstances violated the Eighth Amendment’s prohibition against “cruel and unusual punishment.” After trial the District Court found that double celling at SOCF was unconstitutional and it ordered the defendants to “proceed with reasonable dispatch to formulate, propose and carry out some plan which will terminate double celling at SOCF.”13 The plans submitted were dismissed as inadequate and the defendants appealed, arguing that the District Court had, in effect, held that double celling was “per se unconstitutional.” On appeal the Court of Appeals affirmed, finding that the District Court had held “only that double celling is cruel and unusual punishment under the circumstances at SOCF” and that the findings of the District Court were not clearly erroneous on this point.14
In reversing the District Court and the Court of Appeals, the Supreme Court laid out with precise clarity the limitations upon federal judicial intrusion in state prison administration and applied those limitations particularly to challenges to prison double celling. After declaring that “the Constitution does not mandate comfortable prisons, . . . free of discomfort” or “ideal” conditions of confinement nor does it demand that the conditions in the prisons may not be “restrictive [or] harsh” but merely requires that such conditions “not involve the wanton and unnecessary infliction of pain, nor [be] . . . disproportionate to the severity of the crime warranting imprisonment,” it held that “the double celling under [the circumstances of that case did not inflict] unnecessary or wanton pain [nor was] grossly disproportionate to the severity of crimes warranting imprisonment.”' It pointed out that federal courts, reviewing prison conditions under the Eighth Amendment, were not concerned with whether conditions were the “best” or that there were better “alternatives” but only whether those conditions subjected the prisoner to “cruel and unusual punishment.” The argument that the prison population in a particular prison facility exceeded “design capacity,” or that two prisoners were placed in a cell intended for single occupancy, was dismissed with the comment that “at least three factors influence prison population: the number of arrests, prosecution policies, and sentencing and parole decisions. Because these factors can change rapidly, while prisons require years to plan and build, it is extremely difficult to calibrate a prison’s ‘rated’ or ‘design capacity’ with predictions of prison population. Memorandum of the United States as Amicus Curiae 3, 6. The question before us is not whether the designer of SOCF guessed incorrectly about future prison population, but whether the actual conditions of confinement at SOCF are cruel and unusual.”15 It restated what it had earlier said in Bell that the opinions and recommendations of penal experts which generally describe merely “goals recommended by the organization in question” “simply do not establish the constitutional minima” which are “whether the actual conditions of confinement . . . are cruel and unusual.”16 It said that it might [427]*427be agreed, too, that “double celling is not desirable” but observed that does not make it unconstitutional.17 Of course these statements of the Court, finding double celling not unconstitutional, were made in connection with the circumstances in the case before the Court. But the facts in these cases as well as the rulings in the court below, are almost a carbon copy of the facts in the cases before us.
Moreover, during the time that the law with respect to double bunking and double celling, the two primary issues in these cases, was evolving, changes were occurring in conditions in the Maryland prison facilities themselves. In an “energetic” and “good faith” effort to meet the deadlines fixed in the Decrees, the defendants had, in accordance with our suggestion in Johnson v. Levine, begun the construction of new prison facilities with the purpose of avoiding any overcrowding in its prisons. One of those new facilities (the Jessup Annex) was at the time of the hearing before us, for all practical purposes, completed. This facility was modern in every detail and was the equal of, if not superior to, the facility involved in Rhodes. The defendants were proceeding, also, with the construction of a modern, new Reception Center. But, while this was taking place, the defendants had been suddenly in late 1980 faced with an unexpected rise in their prison population which they, even with their new construction, were not prepared entirely to cope with. The defendants were not responsible for nor could they control this unexpected increase. As the Court in Rhodes said, “it is extremely difficult to calibrate a prison’s ‘rated’ or ‘design capacity’ with predictions of prison population.”18 This unanticipated increase in prison population compelled the prison officials to consider new methods for meeting their problems of overcrowding. The proposal for double celling and double bunking was the result.
It is quite clear from what has been said that the defendants have made an adequate showing justifying a review anew, in the light of the clarification in the law and the changes in conditions, of the remedy imposed by the District Court. That remedy, however, does not strictly apply to the Jess-up Annex, which was not the subject of complaint in any one of the cases before the District Court. For this reason it is unlikely the defendants were obligated to seek prior approval in these proceedings for double celling at such facility. However, the proposed double celling at Jessup was related to compliance on the defendants’ part with the provisions of the Decrees covering the other three facilities which are directly involved in these proceedings. Under those circumstances, the defendants, in our opinion, acted with becoming deference to the District Court in seeking its approval for the proposed double celling as a remedy for overcrowding at the older, less modern institutions. We accordingly deal with the issue of double celling at the Jessup Annex on the assumption that such issue was properly before the District Court in these cases. Under the authority of Rhodes and on the basis of the established and planned conditions at the Annex, we conclude that the District Court erred in refusing to approve double celling at the Jessup Annex under the terms and conditions proposed by the defendants.
The District Court, however, refused to approve double celling, holding that as a matter of federal constitutional law double celling is not permissible in the prisons of Maryland. In declaring this absolute rule proscribing double celling, the District Court did not relate its decision to the condition of the prison facility where double [428]*428celling was proposed. It decreed the rule applied equally to “new as well as old prison buildings.” In conformity with this ruling, it did not take notice of the modernness of the Jessup Annex. The only comment it made about the new facility at Jessup was that it “was not designed for double celling.” Other than that bare comment, it faulted none of the facilities or procedures at the new modern prison; it refused to approve double celling at the Jessup Annex simply because, as it flatly put it, “double celling is not an acceptable solution to the problem of overcrowding in Maryland’s prisons” and “two prisoners should not be confined to a single cell.” That such a strict and inflexible application of the constitutional prohibition on “cruel and unusual punishment” in the prison environment, made without any consideration of conditions at the prison where double celling was proposed other than the mere design capacity of the prison, is clearly at variance with Rhodes v. Chapman, supra, and with the conditions at the Jessup Annex.
The facilities and conditions of confinement at the Jessup Annex are as good, if not better than those at SOCF. The cells are roughly the same size; there is no significant difference in the recreational opportunities; the provision for food, medical, dental and psychiatric services are comparable; the facilities in the cells are practically the same; all in all, both facilities — those in Ohio and those in Maryland — are in line with the facilities in the most modern penal institutions. The defendants are just as entitled as were the defendants in Rhodes to institute double celling at the Jessup Annex and, using the words of the Supreme Court in Rhodes, the District Court had “no authority to consider whether double celling ... [at Jessup Annex] was the best [or proper] response to the increase in [Maryland’s] state-wide prison population.” The same result is required in these cases.
Double bunking in the dormitories, the other proposal of the defendants under review, would, it is true, increase by a maximum of 150 inmates the prison population in the dormitories, and thus, unlike the double celling request, would, if approved, represent a departure from the original Decree of the District Court, setting an absolute maximum on the number of prisoners in such dormitories. The District Court gave no reason for its denial of the request to double bunk. Apparently, it assumed that double bunking was per se unconstitutional. If this was its reason for denial of the request, Bell was a clear answer in reply. Nor do we find the point that Bell involved pretrial detainees and not convicted prisoners important.19 As we have seen, both the District Court and the Court of Appeals in Bell conceded that double bunking of- convicted prisoners was not “punishment” and, if it was not “punishment,” it would not fall within the proscription of the Eighth Amendment, absent other circumstances rendering it “cruel and unusual punishment.” The District Court has not identified nor have we perceived any other circumstances which could impart to double bunking in the dormitories an unconstitutional character.
The proposed double bunking in the dormitories contemplated the removal of all bunk beds in excess of 75 per dormitory and the double bunking of the remaining 75 bunk beds, thereby increasing the prison population housed in these four dormitories by 150 inmates. The additional inmates would be double bunked “for a period no greater than 120 days and, if possible, no more than 60 days” under the plan. As the [429]*429District Court observed in its original opinion in Johnson, there are no cells in the dormitories and the inmates assigned there have far greater freedom to move about than inmates confined in cells.20 In its original order in Johnson, the District Court, after a personal inspection of the dormitories, compared favorably the space available for each inmate in the dormitories (55 square feet) with that available to the two inmates double celled in other parts of the facility (“forty square foot cells . . . occupied by two inmates”). It also found that “[t]he dormitories themselves are kept reasonably clean, and sanitation in the shower and toilet areas is adequate.” In fact, it found that conditions in one of the dormitories were “obviously superior to those elsewhere in the institution and clearly meet constitutional requirements.” It accordingly held that “the dormitories [met] constitutional requirements” and refused to order a reduction in the number of prisoners confined in any of the MHC’s' dormitories.21 We perceive no reason why those same comments should not apply to conditions after double bunking had been inaugurated in the dormitories. Even after the addition of the new inmates, the actual space available to each inmate will remain substantially the same.
Taking into consideration the changed circumstances freely recognized by the District Court, which made it plain that the timetables established in the Decrees of the District Court were not reasonably “achievable,” despite the defendants’ “good faith” efforts to meet such timetables, the defendants were entitled to a modification of the Decrees herein; and, so far as those Decrees sought to declare double celling or double bunking in the Maryland prisons were not “permissible” per se under federal constitutional law, they were in error. As we have already said, the conditions in the Jessup Annex met the standards found to be constitutional for double celling in Rhodes v. Chapman, and the conditions in the four dormitories where the State authorities proposed to double bunk prisoners were the equal, if not superior, to those found within constitutional limits in Bell v. Wolfish. We accordingly vacate the District Court’s order disapproving double celling at the Jessup Annex and double bunking, under conditions stated in the defendants’ proposed plan, in four of the dormitories at MRDCC.
Finally, the defendants have appealed that portion of the District Court’s order which commands them to “transfer approximately fifty state prisoners who voluntarily agree to be transferred” to the Federal Bureau of Prisons. We perceive no objection to this provision, if the double celling permitted at Jessup Annex and the double bunking at the dormitories do not relieve the overcrowding in the three institutions in controversy (MHC, MRDCC and MHI-H), and, with this provision, we affirm this part of the District Court’s order.
All three actions, which have been consolidated in two actions, are remanded to the District Court with instructions to fashion new Decrees authorizing double celling at the Jessup Annex and double bunking in the dormitories at MRDCC, both under the terms and conditions set forth in the proposal of the defendants. Further, the Decree finding civil contempt against the defendants and imposing sanctions in the MHI-H proceedings (Washington v. Keller) is specifically vacated.
Since all of these cases are interrelated and involve in one aspect or another a single prison system, judicial time will be saved and the convenience of the parties will be served if, on remand, all cases are consolidated and assigned to a single judge, and we so direct on remand.