In a message dated 7/6/01 1:57:57 PM Central Standard Time,
rwst@cox-internet.com writes:
<< According to TM 9-2320-209-10-1
VEHICLE /BRIDGE CLASSIFICATION.
E - Class number of vehicle with no payload.
C - Class number of vehicle with cross-country payload.
H - Class number of vehicle with highway payload.
For a M35A2
E - 6
C - 8
H - 11
>>
While the above is correct, I believe it is worthy of further explanation....
The bridge weight classification system is quiet complicated, varying for
wheeled vehicles, tracked vehicles, spacing of axles, speed and number of
lanes. I have several manuals on this subject, if anyone wants specifics,
let my know and I'll try to supply them.
If you are ever on an active installation, you can note that bridges have
classification numbers assigned to them. I say numbers, because there is one
for tracked vehicles and one for wheeled vehicles. These can be seen at Ft.
Campbell, Ft. Knox, and Ft. Riley, as well as others.
Similarly, vehicles have bridge weight classification numbers assigned to
them, and each vehicles classification is listed in a number of manuals. And
while there is often a direct relationship between the vehicles gross weight
at the class number, it can occasionally vary due to, among other factors,
speed and axle spacing. As examples, the M125 truck, with a weight empty of
14.39 tons, carries an empty bridge classification of 12, while a certain
wheeled tractor with a weight of 21.2 tons has a bridge class of 33.
The bridge weight classification numbers mounted on the front of Post-WWII US
military vehicles are as a rule changeable, and when properly operated they
are changed, as noted above, depending upon how the vehicle is operated and
loaded.
The numerals should be changed depending upon load, further, the top plate
has a red "C" on its flip side. When a vehicle is being used as a prime
mover, that plate should be flipped and the numbers changed to reflect the
COMBINATION bridge weight classification of the lash up. When the trailer is
disconnected, the "C" should be hidden.
To make this even more difficult, you don't just add the weights, or even
bridge classifications, to yield the COMBINATION bridge classification
(remember axle spacing, etc., enters into this). As an example:
M270 low bed trailer empty weight 8.75 tons
bridge classification 8
M246 tractor wrecker empty weight 16.42 tons
bridge weight classification 15
Combination weight M246/M270 25.17 tons
Combination weight classification 19
All of the above numbers are from TB 746-93-1, by the way
If you find this is confusing, don't feel bad, I have at least 5 manuals that
go into this subject at length. Please feel free to use this information in
your restorations, but since it is the crux of an upcoming article, please do
not reproduce it without asking.
Hope this helps,
David Doyle
This archive was generated by hypermail 2b29 : Tue Aug 07 2001 - 09:34:11 PDT