Bridge weight markers

[John S-B]

I'm not able to find any info on what the numbers on the data plates mounted on the front of MV's mean. I assume it tells the engineers what certain vehicles weigh so they aren't allowed to cross temporary bridges that can't hold them, but they could just stencil weights on vehicles if that's the case. We never had cause to have to rely on them so I never learned their true function. Anybody got some insight into this? And yes, I did search...

 

[steelandcanvas]

Try "bridge plate".

 

[General Mcgregor]

They are not always stenciled because they change if you are towing a trailer.

 

[M35A2-AZ]

The number is in tons that your vehicle and if you have a trailer, what the total weight is in Tons. For a empty deuce you would have a 07 on the front.
An empty deuce and a empty m105 you would have 09.

 

[73m819]

The number is in tons that your vehicle and if you have a trailer, what the total weight is in Tons. For a empty deuce you would have a 07 on the front.
An empty deuce and a empty m105 you would have 09.

the C stands for combination if a truck is pulling a trailer, the MAX combe weight

EXP=the 819
no trailer = E in the -10 is 16
w/trailer = C in the -10 is 22

 

[cranetruck]

The number is in tons that your vehicle and if you have a trailer, what the total weight is in Tons. For a empty deuce you would have a 07 on the front.
An empty deuce and a empty m105 you would have 09.

There is another consideration besides weight and that's weight distribution. For example, my 16,500 lb 8x8 (two front axles) has a "07" for its bridge plate number, so it's not exactly going by the weight.
Should be a formula somewhere....found this, which suggests that it's more involved...still searching...

 

[M813rc]

Quote:
Originally Posted by M813rc
Okay, from my copy of FM 5-36 dated May 1985-

To get a weight classification, the following is used:
Weight (empty, loaded, and loaded for highway);
Load on pintle or 5th wheel;
Tires (number per axle, size and PSI);
Distance between axles;
Distance from nearest axle to pintle or 5th wheel;
Outside and inside width of tires or tracks;
Length of track in contact with the ground;
Vehicle NSN.

This all gets sent to STRBE-NBE at Ft Belvoir where they perform some ceremony that quite possibly includes waving an intoxicated newt around above the numbers and they give you the weight classification.

OR, you can look and see if they have already done their rituals and your vehicle is on the Standard list in appendix C-3;

or you can get a field expedient number by using 85% of the vehicle gross weight.

The actual bridge plate number is apparently derived from a fairly complex formula. The route recon manual says that in the absence of your actual setup being listed, you should use 85% of your total weight.

I saw a post recently that said there is a newer manual coming out, but I couldn't find it to list the FM # here.

Cheers

 

[clinto]

http://www.steelsoldiers.com/deuce/64738-nube-question-what-those-discs-grill.html

http://www.steelsoldiers.com/cucv/54634-bridge-plate-numbers.html

RELATED: http://www.steelsoldiers.com/paint-bodywork/9039-bridge-plate-yellow.html

 

[John S-B]

Well I should've known, that seems like a real dumass way to figure weight classifications. Seems like a better and simpler way to do it would be to just post a weight limit on the bridge. Every time you put a different load on the truck it weighs different. You'd have to change your plate every load. And I know we had some deuce's that were way over loaded sometimes. If you just had a weight limit on bridges, the driver should know roughly what his truck weighs most of the time.

 

[Truckoholic]

I am going to be putting my bridge plate back on after painting my truck over the next few days, and I too have been curious to know what numbers I should put on there. But it appears entirely too confusing for me to figure out, so maybe I will just put it back at 69 like it was when I bought it

 

[MWMULES]

They did and they still do

 

[73m819]

Well I should've known, that seems like a real dumass way to figure weight classifications. Seems like a better and simpler way to do it would be to just post a weight limit on the bridge. Every time you put a different load on the truck it weighs different. You'd have to change your plate every load. And I know we had some deuce's that were way over loaded sometimes. If you just had a weight limit on bridges, the driver should know roughly what his truck weighs most of the time.

THIS is why the TRUCK bridge plate shows the MAX truck weight number, the bridge DOES NOT care if trucks are UNDER the RATED bridge WEIGHT, JUST if the trucks ARE OVER

 

[Jake0147]

Well I should've known, that seems like a real dumass way to figure weight classifications.

It kind of does at first, but there is more to what a bridge can carry than just weight. The wheel base, and the distance between individual axles will determine how many of the structural supports below the bridge will be bearing what percentage of the weight of which axle at any given instance. The more structural members the weight can be divided among at any given time, the more the bridges capacity will be. The more tires there are to divide the weight, the less strength in the bridges decking will be required to transfer that weight to the structural members. Structural capacity is not a simple measurement by any means. The bridge plate idea is to greatly simplify that.

As for letting drivers decide...
Yeah, sure. Bridges look a lot stronger in adverse circumstances. Really they would have two choices.
They'd have to train drivers with algebra, trig, calculus, material properties, bridge construction technique for every bridge ever invented, how to identify them on the fly, and make them good enough at it that they could work out what they need to know on a case by case basis...
Or they would have to rate the bridge at a single weight for the shortest, narrowest vehicle that would ever cross it in the course of it's designed lifetime. In which case the bridge would have a weight rating, depending on the type and construction, that could be anywhere from 30 to 60 percent of it could carry with more wheelbase, more wheels, etc. Floating bridges are even worse. That would be a LOT of infrastructure, manpower, and delays to provide that much overkill on a portable basis, as many of the bridges in question are.

 

[John S-B]

I don't think the vast majority of soldiers have a clue how they work, I know we were never trained on their use, even in convoy ops.

 

[73m819]

I'm not able to find any info on what the numbers on the data plates mounted on the front of MV's mean. I assume it tells the engineers what certain vehicles weigh so they aren't allowed to cross temporary bridges that can't hold them, but they could just stencil weights on vehicles if that's the case. We never had cause to have to rely on them so I never learned their true function. Anybody got some insight into this? And yes, I did search...

THIS is why the TRUCK bridge plate shows the MAX truck weight number, the bridge DOES NOT care if trucks are UNDER the RATED bridge WEIGHT, JUST if the trucks ARE OVER

WHO ever designed/ inspected the bridge, assigned a MAX load rating, this may anywhere from 1 to whatever, this is the MAX bridge load rating at any one time. if the bridge is rated at 12, a max loaded deuce is say rated at 6, so 2 deuces could be on the bridge as the same time, but only 1 max loaded m821 could be on the same bridge since it is rated at 12.

The truck rating has the length, MAX weight, axle spacing , ect all ready figured in.

For example a 816 is rated at 18 and the 819 at 16, even though the 819 is heavier, it is longer thus the weight is spreed out more so the lower bridge rating number

 

[touringfordor]

I took this up with an old college buddy who was a career man in the Army combat engineers. He said they used a formula that took into account axles, wheelbase, track, weight, etc., but couldn't find his old TM on it. I did find this post when researching bridge plates:
Military-Vehicles: Re: [MV] Bridge Plate Letters and Numbers fo

Basically, a cross-country loaded deuce is 08, highway loaded 11, empty 06. Unless you have a trailer.....

 

[jasonjc]

I am going to be putting my bridge plate back on after painting my truck over the next few days, and I too have been curious to know what numbers I should put on there. But it appears entirely too confusing for me to figure out, so maybe I will just put it back at 69 like it was when I bought it

Gee looking at table 1-1 page 1-9 of TM 9-2320-260-10 for the M813 or

Table 1-5 page 1-16 of TM 9-2320-361-10 Dec 1988 for the M35A2.

If looking at a table is entirely too confusing for you to figure out, .....

 

[Chief_919]

The plates are not for the drivers. They are for the Engineers and MP's who will be posted outside the bridge managing traffic. They provide an easy for them to spot a vehicle over the rated limit for the bridge.

The primary use is for float and Bailey style bridges construted by the Engineers, but you will also find MP's at other bridges managing the mount of traffic over it.

A bit of how it works from FM 19-25:

Types of Bridge Crossings

Due to age, structure material and strength, bridges have varying capacities and classifications. Engineers are responsible for determining the capacity of a bridge. Military vehicles are classified by load weight, ranging from 4 through 150. Military Police enforce the capacity decisions made by the engineers. Bridge crossings are classified by two types--normal and special (caution or risk).
NORMAL BRIDGE CROSSINGS

Normal crossings are made when the vehicle class number is equal to or less than the bridge classification. The crossing may be one-way or two-way. During one-way operations on a two-way bridge, vehicles should drive down the center of the bridge. On-coming traffic must be halted, thereby causing a temporary obstruction to two-way flow of traffic. The minimum vehicle interval is 30.5 meters (100 ft) and the maximum speed is 40 kph (25 mph).
Special Bridge Crossings

Special crossings occur when the vehicle class number exceeds the bridge classification. They are classified as either caution or risk crossings. They are authorized only under exceptional conditions by the military area authority or civil authorities, if appropriate.
Caution Crossing

When the vehicle class does not exceed 25 percent of the bridge class, it's a caution crossing. Vehicles must stay in the center of the bridge, maintain a minimum of 50 meters interval and the maximum speed is 8 mph (13 kph). Stopping, accelerating or shifting gears is prohibited.
Risk Crossing

This is when the vehicle class exceeds 25 percent of the bridge classification and is authorized only in grave emergencies. An engineer officer must inspect for damage after each crossing and have the damage repaired before traffic resumes. Vehicles must stay in the center and cross one at a time. Maximum speed is 3 miles per hour. Stopping, accelerating, or shifting gears is prohibited. Tanks must steer by using clutch only.

The plate is there so the MP's can quickly identify the max weight that vehcile combo could present.

 

[USAFSS-ColdWarrior]

I have heard the Operational Title of: BRIDGE MARSHAL when referring to the MP or Engineer monitoring approaching vehicles and then "metering" their process/proceeding over the structure.

He is assigned the responsibility for the continued usefulness of the bridge and commonly could be heard referring to the structure as MY BRIDGE, because he knew it would be HIS A$$ that would get reamed if HIS BRIDGE collapsed.

 

[sandcobra164]

All of my trucks "Proudly Display" 95 because that is "Lightening McQueens" number. I tried to explain the importance of bridge plates to my 4 year old but gave up pretty quick in that endevor. Put what you want on the bridge plate, if you want it accurate, put 07 for an empty Deuce, put a C09 for a Deuce pulling an M105 or put 95 on it if your kids love "CARS" and you don't care about bridge plates anymore.