Bridge Class – U.S. Army

Bridge Classification Signs and Plates on Allied Vehicles and Tanks during WWII

Introduction

During World War II, the effective movement of military vehicles and tanks across various bridges was a critical aspect of strategic mobility. To address concerns about potential damage to bridges from vehicles exceeding their weight capacities, the Allied forces implemented a comprehensive system of Bridge Classification Signs and Plates. This system aimed to categorize both bridges and vehicles based on their weight capacities, ensuring safe passage and minimizing the risk of structural damage. This essay explores the historical development, implementation, and significance of the Bridge Classification Signs and Plates used by the Allied forces during WWII.

Historical Background and Implementation

The origin of the Bridge Classification System can be traced back to the early stages of World War II. In the summer of 1940, the War Office recognized the increasing risk of bridge damage caused by vehicles exceeding their weight limits. To mitigate this risk, a system of classification and marking for both bridges and vehicles was adopted. The regulations in 1940 initially designated bridge classes as 5, 9, 12, 18, and 24, while by 1944, the system expanded to include classes 5, 7, 9, 12, 16, 18, 20, 24, 30, 35, 40, 50, 60, and 70.

Bridge Classification Signs

Bridge Classification Signs were instrumental in conveying crucial information about the weight capacity of a given bridge to approaching vehicles. These signs were typically discs, ranging from 6 to 9 inches in diameter, painted yellow and adorned with black numbers representing the weight class. The signs could either be metal plates attached to the vehicle or painted directly onto it. They were commonly positioned on the right front fender, and in some cases, replaced the right front headlight.

The numbering system denoted the maximum weight class of vehicles that could safely cross a specific type of bridge. These weight classifications did not necessarily reflect the actual weight in tons but were derived from factors such as axle loading, distance between axles, and impact factor. The 1943 manual “TM 5-277” provided detailed information.

Vehicle Classification and Marking

To complement the bridge classification system, Allied vehicles and tanks were classified based on their weight, and corresponding markings were applied. Each vehicle had a black numeral(s) on a yellow disc indicating its weight class, attached to or painted on the front of the vehicle. Motorcycles, classified as Class 1 vehicles, were an exception, and they did not have bridging discs.

Vehicles towing guns or trailers received double classifications. The upper number denoted the class of the complete “train” (vehicle and attached equipment), while the lower number indicated the class of the “tractor” (vehicle) alone. In cases where vehicles towed other vehicles, the classifications of both vehicles were added to determine the overall classification.

Challenges and Solutions

Implementing and maintaining this classification system posed challenges in the field. The visibility of the classification signs was crucial, and efforts were made to ensure they remained visible even when vehicles were camouflaged. Canadian Army Training Memorandum No. 22, published in January 1943, emphasized the importance of covering these signs to prevent them from attracting unnecessary attention.

Vehicle Types and Classifications

Military Training Pamphlet 74 Part IV, published in May 1944, listed various vehicle types and their corresponding bridge classifications. This information provided a comprehensive overview of the diverse fleet of military vehicles and tanks used during WWII, helping commanders make informed decisions regarding bridge crossings.

Conclusion

he WWII Allied Bridge Classification Signs and Plates played a crucial role in ensuring the safe passage of military vehicles and tanks across bridges. This systematic approach to bridge and vehicle classification helped minimize the risk of structural damage and contributed to the overall efficiency of Allied military operations. The implementation of this classification system, as detailed in historical documents such as 1943 “TM 5-277,” underscored the meticulous planning and attention to detail that characterized Allied military strategies during World War II.

Military Training Pamphlet 74 Part IV published in May 1944 and the U.S. 1943 “TM 5-277”  listed the following vehicle types and their bridge classifications (the list is also useful for providing a look at vehicle designations as the army of the time used them):

TM 5-277 (1943) Our own historical research

Bridge Classification – U.S. Army – Vehicles, Trailers and Tanks (1943)

Class	Type	Category	Class
1	Motorcycle	Motorcycle	1
1	Trailer, small 1/4 ton, 2-wheel, (TM 10-1281 & TM 10-1230) for Jeep 4×4 Willys / Ford	Trailer	1
2	Trailer, medium 1 ton, 2-wheel (Ben Hur), (TM 9-883) for like Dodge / GMC	Trailer	2
2	Truck 1/4 ton, Jeep / Reconnaissance truck	Truck	2
2	Truck 1/4 ton, Jeep 4×4 Willys / Ford	Truck	2
3 over 2	Truck 1/4 ton, Jeep 4×4 Willys / Ford, w/trailer small	Truck + Trailer	3 over 2
3	Trailer, heavy M10 Ammo, 2-wheel, (TM 9-333)	Trailer	3
3	Truck 1/2 ton, Dodge VC-series, no trailer	Truck	3
4	Ambulance, 3/4 ton	Truck	4
4	Truck 3/4 ton, Dodge 4×4 WC-series, (TM 9-808) no trailer	Truck	4
4	Truck Light	Truck	4
6 over 4	Truck 3/4 ton, Dodge 4×4 WC-series, (TM 9-808) w/trailer (Ben Hur)	Truck + Trailer	6 over 4
5	Truck 1-1/2 ton	Truck	5
5	Truck 1-1/2 ton, Dodge 6×6 WC62-63, (TM 9-810) no trailer	Truck	5
5	Truck 1-1/2 ton, Dodge VF-series, no trailer	Truck	5
7 over 5	Truck 1-1/2 ton, Dodge 6×6 WC62-63, (TM 9-810) w/trailer (Ben Hur)	Truck + Trailer	7 over 5
6	Truck 1-1/2 ton, w/105-mm How	Truck + How	6
7	Armored Car M8	Armored Car	7
10	Half-Track like M3	Armored Car	10
10	Truck 2-1/2 to 5 ton	Truck	10
15	Tank, Stuart	Tank	15
16	Tank, destroyer Hellcat	Tank	16
21	Trucks over 5 ton	Truck	21
30	Tank, Sherman	Tank	30
34	Tank, Pershing	Tank	34
6 or 7	Truck 1-1/2 ton, w/1-ton trailer (*)class 6 or 7, depending manuals & photo’s	Truck + Trailer	6 or 7
7	Tractor, D-4, w/dozer	Tractor	7
8	Car, armored light M8	Armored Car	8
9	Car, half track M2	Armored Car	9
9	Truck 2-1/2 ton, w/105-mm How.	Truck + How	9
9	Truck 2-1/2 ton, w/1 ton trailer	Truck + Trailer	9
11	Grader, road mtzd. (Engr.)	Grader	11
11	Truck 4 ton wrecker	Truck	11
11	Truck 2-1/2 ton, w/155-mm How. Carr. M1	Truck + How	11
12	Crane trk-mtd. (Engr.)	Crane	12
12	Tank, light M2A4	Tank	12
12	Trk-tractor, 4-5T w/semi-trailer fuel serv. F-2	Truck-tractor + Trailer	12
13	Truck, 4 ton cargo (same as distributor water)	Truck	13
13	Truck, 4 ton ponton	Truck	13
14	Tank, light M3	Tank	14
14	Trk-tractor, 5-6T w/semi-trailer ponton	Truck-tractor + Trailer	14
15	Crane trk-mtd., w/crane atchmnts. trailer	Crane H-10 loading (AASHO)	15
15	Tractor, D-7 w/dozer	Tractor	15
16	Motor carriage, M8	Motor Carriage	16
16	Tank, light M5	Tank	16
16	Truck, wrecking C-1 (AC)	Truck	16
16	Truck, 4 ton, w/155-mm How., carr. M1	Truck + How H-10 loading (AASHO)	16
17	Truck, 2-1/2 ton, w/8 ton trailer	Truck + Trailer H-10 loading (AASHO)	17
18	Tank, light 18 ton	Truck H-10 loading (AASHO)	18
18	Truck, 6 ton, cargo	Truck H-10 loading (AASHO)	18
19	Truck, 6 ton, bridge	Truck H-10 loading (AASHO)	19
20	Truck, 4 ton. cargo. w/8 ton trailer	Truck + Trailer H-10 loading (AASHO)	20
21	Tank, medium M2A1	Tank H-10 loading (AASHO)	21
21	Truck, 7-1/2 ton, cargo & prime mover	Truck H-10 loading (AASHO)	21
22	Tractor, D-8, w/dozer	Tractor H-10 loading (AASHO)	22
22	Truck, 6 ton, w/3-in. AA M2A2	Truck H-10 loading (AASHO)	22
23	Truck, 6 ton, w/90-mm AA M1	Truck H-10 loading (AASHO)	23
24	Motor carriage, M7	Motor Carriage H-10 loading (AASHO)	24
26	Trk-tractor, 6 ton, w/semi-trailer wrecking C-2	Truck-tractor + Trailer H-10 loading (AASHO)	26
26	Trk-tractor, 7-1/2 ton, w/semi-trailer fuel serv. F-1 (AC)	Truck-tractor + Trailer H-15 loading	26
27	Motor carriage, M12	Motor Carriage H-15 loading	27
28	Truck, 7-1/2 ton, w/155-mm gun carr. M2 & M3	Truck H-15 loading	28
29	Motor carriage, M10	Motor Carriage H-15 loading	29
31	Truck, 6 ton, w/16 ton trailer	Truck + Trailer H-15 loading	31
32	Trk-tractor, 5-6 ton, w/20 ton semi-trailer	Truck-tractor + Trailer H-15 loading	32
33	Tank, medium, M3	Tank H-15 loading	33
34	Tank, medium, M4	Tank H-15 loading	34
34	Truck, 7-1/2 ton w/8-in. Gun carr. M2 transp M1	Truck H-20 loading	34
37	Truck, 6 ton, w/20 ton trailer	Truck + Trailer H-20 loading	37
39	Truck, 7-1/2 ton, w/20 ton trailer	Truck + Trailer H-20 loading	39
46	Tank, assault, T-14	Tank H-20 loading	46
60	Tank, heavy, M6	Tank H-20 loading	60

TM 5-277 (1948) Our own historical research

 

Source info & some other interesting links for extra research:
– Our own historical research and collection by “Army Vehicle Marking . com”
– 1943 & 1948 manuals “TM 5-277”
– U.S. Army Vehicle Markings by Jean Bouchery & Philippe Charbonnier
– www . canadiansoldiers . com
– www . wartimecanada . ca
– www . mapleleafup . net
– forums . g503 . com
– www . wikipedia . org

Index: Brasil, Brazil, Bridge Class, Bridge Classification, Bridge Classification Signs, Bridge Plate, FAB, FEB, Holland, Mexico, Netherlands, Philippines, The Netherlands, U.S., U.S. Airforce, U.S. Army, U.S. Navy, U.S.A, U.S.A.A.F., U.S.A.F.