Bomber Alert Facilities
As SAC began to put its bombers on sustained alert status at selected bases from 1956 forwards, with dispersal planned for 55 bases at the end of the next year, the command also addressed the needs of a specialized alert apron and immediately adjacent crew quarters.
SAC placed its B-36s, B-47s, and early B-52s on alert first through several distinct configurations, near one end or the other of a runway typically lengthened (or built) for the heavy bomber, and with an awareness of the need for alert billeting. The issue was one of location: could planes be placed in a position for immediate takeoff? Could crews reach their aircraft quickly?
SAC's initial time-frame for alert was one hour from notice to takeoff for one-third of its assigned fleet at each of its bases, a change from the six-hour minimum existing before the ready-alert concept. It would become 15 minutes. Both bombers and their counterpart tankers went on alert. The goal was to achieve take-off within the 15 minute window assumed to be required by 1961: by that date SAC anticipated that the Soviet Union would have an operational ICBM, with a "detection to detonation time" of a quarter-hour.
The first step was adjusting to existing conditions. In some cases, crew quarters already were in place reasonably close to the flightline: these became alert quarters. In other cases, temporary quarters were established near the planes on alert. In all instances, this first alert posture used apron parking that was in place. The second step was the design and construction of permanent alert crew quarters, with a definitive alert apron.
SAC had established a formal need for new infrastructure supporting an alert concept very early, in July 1954. At that time, the command sought "alert hangars, organizational maintenance hangars and operational shelters for B-52 aircraft" -the latter still a year away from actual receipt. This plan for alert strongly suggests that SAC was following ADC in its conceptualization of what was required for alert aircraft at the flightline: in fact, SAC would not use hangars or shelters in its final buildout for alert, and would continue to use the double-cantilever hangar for maintenance.
SAC approached the first step toward alert beginning in late 1956 and running through 1958. Some bases, such as Schilling in Kansas, had airmen dormitories near the main bomber parking apron, toward the end of the runway. The time needed to get from these quarters to the aircraft was only three minutes. In this case, as in others, the selected quarters were renovated for SAC alert during 1957. SAC conducted surveys, installation by installation, of its existing buildings to ascertain those that could serve as ready crew facilities. This interim solution focused on barracks able to accommodate one-third of the flight and maintenance crews for an assigned wing, with a few miscellaneous personnel. For the B-47, for example, the sought-after quarters needed to house about 110 men. The building also needed enough space for operations activities, and "should be as close to the flight line as possible."
Both the interim alert crew quarters and the interim alert parking area on the main ramp were perimeter fenced, with secure access gates. The command ordered that installations develop a "colored base layout indicating distances" between parked alert aircraft, alert crew quarters, the messhall, and the parked bombers, with the routes clearly marked in red. SAC then tested this arrangement in operation Try Out, followed by Watch Tower and Fresh Approach.
After establishing an interim policy for alert, SAC undertook the planning needed for a formal alert apron and new permanent alert crew quarters adjacent. Apron assessment, with new construction specifically for alert, moved quickly.
SAC had two generic apron configurations in place by late 1957: a main, rectangular apron for mass aircraft parking, and, "stub parking" for individual planes. Within the Eighth Air Force, these configurations were split about equally. The two categories of configuration, however, are an oversimplification of what actually existed across SAC by 1957. The large, single parking apron did of course still exist, as did patterns of single or multiple taxiways lined with short aircraft stubs-the latter represented by Biggs (Texas), Castle (California), and Loring (Maine). Both of these primary apron configurations often had wing hangars in varying numbers at the edge of the single apron or at the individual stubs.
But by 1957, bomber apron design had begun to seriously change. At Ellsworth, for example, SAC arranged lines of the B-36 and multi-purpose wing hangars perpendicular to the main apron, rather than along its edge. This created short lengths of right-angle stubs, very different from the long stubbed taxiways. By late 1957, Ellsworth had eight such perpendicular stubbed parking areas. Several other bases took this idea further by placing perpendicular parking pens as well as stubs at the end of the runway, facilitating fast takeoff. Griffiss Air Force Base in New York is an excellent example on a large scale; Forbes in Kansas, on a small scale. At McConnell, SAC had eight B-47s, with wing hangars, arranged bracketing the installation's two double-cantilever hangars: six of the B-47s were patterned in a proto-herringbone pattern.
One more situation existed in 1957: hot cargo loading pads lining the taxiway parallel to the main runway at its end. Travis and Campbell Air Force Bases are good illustrations. Both of these installations may have engineered the pads to accommodate the special munitions in their adjacent Q Areas.
SAC selected a tentative alert apron before the close of 1956, aware not only of the configurations across its installations, but also of the alert solution developed by ADC in 1951-1952. SAC revisited the alert apron issue several times during 1957 and 1958. First choice was a parking stub configuration, similar to those at Griffiss and Forbes, with individual stubs at 90-degree angles to a 45-degree alert taxiway and with "earth barricades" between the parked alert aircraft at each stub. During the first half of 1957 SAC built 10 alert aprons of this type.
In the latter half of 1957, SAC changed plans for the alert apron to a herringbone onfiguration -- one where not only was the alert taxiway at 45 degrees, but also the individual aircraft stubs. SAC credited its shift to an analysis of ADC alert aprons, also taking the name from ADC: "Christmas trees." ADC alert aprons were in fact less well defined that what the SAC alert aprons would shortly become. Yet, parking alert aircraft at 45 degree angles was the essence of both alerts. The name Christmas tree stuck for the final SAC configuration, although herringbone was often used in the early written descriptions.
By the close of 1957 SAC formally decided to use the Christmas tree alert apron, leaving the 90-degree stub pattern only at installations where construction was too far along to merit stopping and redesign. In October 1957, just four of the new Christmas tree alert aprons were completed: at Mountain Home (Idaho), Robins (Georgia), Wright-Patterson (Ohio), and Wurtsmith (Michigan).
By October 1957, the Air Force mapped 43 of the SAC alert aprons on its service-wide master plans, inclusive of the 14 built. The figure represented two-thirds of the total program at buildout. SAC designed only a small number of its alert aprons with individual stubs intended to accommodate the B-36; the remainder were planned for the B-52. SAC channeled funds in fiscal year 1957 to alert aprons at seven B-52 bases, and to alert aprons at five "heavy" [B-36] bases in fiscal year 1958.
Immediately after the Soviet launching of Sputnik, SAC alert received $24.6 million in supplemental funding in fiscal year 1958-boosting completion of the program. As such, the apron at Wurtsmith was the first in the program built in the mature Christmas tree pattern explicitly proportioned for the B-52. Wurtsmith, a northern tier base of the middle-to-late 1950s, rejuvenated an AAF/Air Force installation at Oscoda-one that had served as an air proving ground and aircraft artillery training range from about 1939 through 1952.
SAC reassigned some of the aprons originally built for the B-36 in the right-angled configuration to a tanker alert status, choosing others for complete reconstruction as Christmas trees. Where SAC required a priority bombing mission and a right-angled apron was in place, reconstruction or redesign occurred expeditiously. Two such instances were those at Loring (reconstructed) and at K.I. Sawyer, Michigan. The right-angled aprons were uniformly mapped in only a five-stub or a nine-stub size. The Christmas tree aprons varied from a minimum size of four stubs, to a graduated size of seven, eight, and ten stubs. By October 1957, Christmas tree alert included three design schemes: a single large-capacity apron; two nearly equal size aprons angled toward a single taxiway; and, two unequal size aprons (six- and four-stub), again angled toward a single taxiway. In the latter case, several variant patterns existed. Simultaneously with the shift from the right-angled to the 45-degree alert apron, SAC changed its strategy to that of dispersal employing both bombers and tankers, and dramatically reoriented its basing emphasis from the interior of the United States to the northern tier of the country.
When the SAC alert apron program was finished, most aprons were Christmas trees; a limited number were the first generation, right-angled type; and, a few were anomalies. When terrain at the ends of runways did not allow the construction of a Christmas tree without extensive fill, or when purchase of needed additional land was difficult, SAC chose to place its planes on a pre-existing rectangular apron near the end of the runway, or to expand an existing parallel taxiway into a small rectangular pen for alert aircraft. In the case of Travis, SAC reused the hot cargo pads already there. And finally, in a unique solution at Lincoln, SAC placed its 45-degree stubs directly off the end of the airfield's NW-SE runway, converting it in effect to the alert taxiway for the primary 12,900-foot N-S runway. Whiteman would return to this idea in the late 1960s, planning for a Christmas tree directly at the end of its primary runway (unbuilt)-to replace an ad hoc rectangular pen of the late 1950s.
In late 1957 none of the existing alert aprons in any configuration included permanent crew quarters. Individual installations followed the orders from SAC headquarters and adapted barracks and dormitories near the flightline where possible, but this was soon found to be expensive. The Second Air Force influenced the form that a second interim solution would take, with its commander asserting that commercial house trailers were the answer to a ready-made, moveable, interim alert housing.
While the existing renovated flightline barracks and interim alert crew trailers were in use, SAC decided that a single, permanent readiness crew facility sited at the head of the alert apron was the preferred solution to alert housing. Even before trailer service testing, the Air Force mapped plans for consolidated crew quarters, to become known as moleholes, at 15 installations.
At some SAC installations, the command maintained both bombers at its molehole apron and tankers at an adjacent secured rectangular apron. This situation, different from that of either bombers or tankers on secured alert at the molehole, appears to date to about 1964, as SAC put in place its Titan II and Minuteman I missile squadrons and was again seriously changing strategy. In that year and several following, the 416th Bombardment Wing of B-52s and its supporting KC-135s were on alert at Griffiss Air Force Base in New York. Six to eight bombers, and eight to 12 tankers, were on "called" alert during 1964-1966. These alerts were exercises of Bravo and Coco type-the former involving engine starts only, the latter requiring movement of the aircraft to takeoff position.
To accommodate this dual bomber and tanker alert configuration at single installations, SAC again returned to the use of alert trailers at Griffiss, placing 15 four-bedroom trailers in two rows at the end of a rectangular pen in April 1964, with the Christmas tree and molehole across the runway. Alert tanker crews had to meet split launch and non-optimum launch conditions at the base. In the time period while the trailers were set up for alert, the Air Force housed the men in a dormitory nearly two miles from the flightline.
The SAC alert crew quarters, like the SAC command post, were partially below ground structures. Of reinforced concrete and concrete-block construction, moleholes were of two-story height, with one story below ground. These windowless alert quarters were identical everywhere, with tunnel-like egress covered in corrugated steel. In selected cases, due to ground water table conditions, the moleholes were built fully aboveground, with the lower story earthen bermed for semi-hardening. SAC built three sizes of standardized crew quarters: 18,000 square feet (70 men); 22,500 square feet (100 men); and, 31,000 square feet (150 men). The three sizes of molehole perhaps reflected the shifting from the large crew of the B-36 to the much smaller crew of the B-52, then in progress, as well as planning for more bombers on alert at some installations than at others.
The dual bomber-tanker alerts accelerated in the early and middle 1970s, with introduction of the short range attack missile (SRAM). For this program, SAC built fairly elaborate tanker aprons (such as at K.I. Sawyer and Minot Air Force Bases), or heavily modified the existing alert apron at the molehole into a rectangular pen. For many of these pens SAC built undistinguished ready crew housing nearby, either as centralized quarters or as individual units at each parked aircraft (surrounding the pen, or at the former molehole stubs).
Orchestration of alerts for the KC-135s is not as clear as that for the bombers. The B-52 could easily make its target fully loaded, even under adverse fuel consumption conditions. The unknown was a matter of reliable return or need to stay in the air. For any strategic scenario, the KC-135 had a variable transfer radius. The tanker could fly about 1,150 miles to deliver its standard 120,000 pounds of fuel. SAC deployed nearly 800 KC-135s between 1957 and 1966.
New weapons systems of the middle 1970s and middle 1980s caused many of those alert aprons still
useable for bombers to undergo major alterations. For example, SAC enlarged the five-stub Christmas
tree at Barksdale (Louisiana) to seven stubs, and subsequently to nine stubs, to accommodate the SRAM (1972-1974) and air-launched cruise (ALCM) deployments during the final phase of the Cold War under President Reagan. Both of these weapons systems have nuclear warheads, with the radical ALCM a ground-hugging, self-guided missile. Each system required that SAC construct additional ancillary
buildings at the perimeter of the alert apron, inclusive of power station, surveillance tower, a reserve fire team and security structure, and family visitation quarters. In some instances, SAC built four to six readiness crew quarters at intervals along the perimeter of the apron, and often the molehole itself was enlarged by 50 percent.
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