SB 5-11
DEPARTMENT OF THE ARMY SUPPLY BULLETIN
RIBBON BRIDGE INTERIOR BAY AND RAMP BAY
ROADWAY TO BOW PONTON LATCHES
Headquarters, Department of the Army, Washington, DC
30 November 1981
1. Purpose. This bulletin is applicable to the latches on
c. The retrofitting of the 413 bays identified above to
Bow Pontons for Bays used on the Ribbon Bridge
the new configuration with not be applied based on results
Systems managed by the US Army Troop Support and
from a cost analysis study conducted by TSARCOM.
Aviation Materiel Readiness Command and provides
d. Both the old style short latch bays and the new
guidance for replacing bow pontons.
style long latch bays will be kept in their original
configuration. This means that a bay with short latches
2. Scope. This bulletin applies to users of the Ribbon
that requires a bow ponton change must be replaced in
Bridge System.
entirety because the old style bow ponton is no longer
3. General. a. The Ribbon Bridge System was initially
available. The mixing of pontons with short latches with
fielded with a short roadway to bow ponton latch NSN
pontons with the new longer latches will not be permitted.
5420-00-507-7051 (97403/13218E4357) which measured
If an old style bow ponton becomes damaged beyond
nine inches total length. This latch is known as the short
repair, the entire bay will be reported to this Command,
latch. In 1978, an Engineering Change was approved to
ATTN:
DRSTS-SDDMT, on a DA Form 3590 and
change the interior and rampbay latch receptacles by
TSARCOM will furnish disposition instructions. Since the
relocating the receptacle flush with the edge of the bay
replacement of pontons has only occurred two times in
instead of originally protruding about two inches beyond
over five years of fielding experience, only minimal
the edge of the bay. This change made it necessary to
replacement actions are anticipated.
introduce a new roadway to bow ponton latch,
4. Safety. Following are areas of concern for safety
97403/13222E0545, which measures 10 1/4 inches total
hazards: a. Use of a bay with damaged receptacles. A
length. This latch is known as the long latch. The
bay with damaged receptacles could fall under load and
purpose of the relocation of the receptacle is to make the
result in a bow ponton folding upward and into personnel
receptacle less vulnerable to damage when the bay
or equipment on the bridge. If this did happen, serious
comes in contact with a hard surface during launch and
injury or death and equipment failure would be probable.
retrieval operations.
The use of a bay with damaged receptacles is not likely,
b. At the time the Engineering Change was applied
however, because of the high visibility of the
to the bow ponton latches, 413 interior and ramp bays had
latch/receptacle during the bay pre-inspection or bridge
been produced, and therefore, are in their original
set up. These checks are required to be performed by the
configuration of short 9" latches with protruding
operator and raft commanders prior to use and prior to
receptacle. The serial numbers of the bays found on the
actual connection of the latch.
end item data plate are as follows:
b. Use of a bay with the wrong latch installed. A
Interior Bays-
short latch, if installed on the wrong bay, will not reach
CONDEC Contract DAAK01-73-C-5996
and cannot be connected. This condition would be
S/N 001 to 250
immediately apparent to the operator who tried to connect
CONDEC Contract DAAK01-77-C-5660
the latch with the receptacle. A long latch, if installed on
S/N 2307-001 to 2307-066
the wrong bay, will overreach by 2 1/2 inches. The
Space Contract DAAK01-76-C-5613
technical manual requires latch receptacle adjustment so
S/N 66981-001 to 66981-016
that the "T" on latch clears the high point of the receptacle
Ramp Bays-
by approximately 0.0625 in (1/16 in). This adjustment is
CONDEC Contract DAAK01-73-C-5996
impossible with an incorrect latch installed. The high
S/N 001-50
visibility of the latch/receptacle coupled with the
CONDEC Contract DAAK01-77-C-5660
requirement for-both operator and raft commander to
S/N 2306-001-2306-025
check these connections makes use of a bay with
Space Contract DAAK01-76-C-5613
S/N 6698R-001-6698R-006
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