1 January 2005
with change 25 October 2006
overhead door at the opposite ends.
4-3.9.2 The workbays are the heart of the OMS. The other support areas are normally
located as closely adjacent to the workbays as possible under the exiting requirements
of NFPA 101; consider locating most of them off a corridor into the workbay, with the
other end of the corridor as their exit path. The functional layout should allow for the
future addition of workbays, if possible.
4-3.9.3 Water runoff from workbay cleaning operations will be collected in a trench
drain located inside the overhead door and emptied into a grease/oil separator
connected to the sanitary sewer. Designer should verify environmental requirements for
drainage with USAR Installation, and local codes and regulations
4-3.9.4 Welding is typically not authorized in an OMS. If authorized, a code-compliant
hood or room must be provided. Comply with NFPA 70 Article 511 and NFPA 51B; a
welding room would require double doors with a vestibule between if it opens to the
workbays. If welding is not authorized, no provisions will be provided for meeting this
requirement. The designer should verify power requirements.
4-3.9.5 The workbays typically are taller than the other OMS supporting spaces with
a 4.3 m (14 ft) minimum clear height, resulting in differing roof and wall heights for the
two areas. In instances where it becomes more economical to construct the OMS with
one roofline, use of the area above the ancillary shop spaces for additional storage and
mechanical equipment space is discouraged. The designer must verify required clear
workbay height with Tenants vehicle sizes.
4-3.9.6 The basic dimensions of the workbays are 20 ft (6.1 m) wide by 40 ft (12.2 m)
long, which includes circulation space along the 20 ft (6.1 m) width. End workbays are
authorized an additional 4 ft (1.2 m) of width on their outboard side to provide circulation
space. Trench drains are located approximately 5 ft (1500 mm) from the exterior wall,
and the floor slopes 3 in (75 mm) to them as shown below.
4-3.9.7 Concrete aprons serve as outdoor workbays, especially for portable hydraulic
hoists, and will be 36 ft (11 m) in depth.
4-3.9.8 Vehicle exhaust drops should be located in each workbay. The drops must be
of sufficient flexibility and length, and have appropriate terminations to adequately serve
the units vehicles.
4-3.9.9 Designers should pay particular attention to coordination of systems in the
space above the workbays. Lights, space conditioning, exhaust drops, power/light reels,
overhead doors, etc., compete for space and must be coordinated for space
4-3.9.10 Overhead workbay doors are typically 16 ft by 14 ft (4900 mm wide by 4300
mm high). Provide 6-inch diameter concrete filled with a concrete dome top, heavy
weight steel protective bollards inside and outside of overhead door jambs and at