Hi fellas,
I'm in the process of building a couple of trailers to complement my Convoy dio & need to ask a couple of questions.
I'm building an M149 water trailer & an M105 1.5ton trailer both from Perfect Scale Modellbau of Germany.
So, my questions are:

1) When these trailers are being towed what happens to the third wheel or stabilising wheel (I think that is what it's called!) near the hookup at the front of the trailers? Is it stowed horizontally with the chassis or is it removed completely & stowed elsewhere?

2) Are the trailers connected in any way to the tow vehicles electrical system for rear brake lighting, etc?

3) What about brakes? Is there an air line from the tow vehicle controlling the trailers brakes?

Any help would be greatly appreciated, as always.

Joe.

OK Joe...here is some trailering 101

1 - The "third" wheel folds up into the yoke portion of the frame. The pull handle on the wheel unlocks the wheel from either its stowed or down position

2 - There is an air brake connection, a black hose which connects to the air connection at the rear of the vehicle.

3 - On the oppisite side if the traile is a black cable which connects to the tow vehicle aux. electrical jack at the rear of the vehicle.

Hope that helps

Rounds Complete!!

Hi Joe

Maybe this would help ?
http://www.tpub.com/content/operatormanuals/TM-9-2330-213-14-P/TM-9-2330-213-14-P0042im.jpg
http://www.tpub.com/content/operatormanuals/TM-9-2330-213-14-P/TM-9-2330-213-14-P0026im.jpg


Frenchy

There are also a pair of safety chains that are attached to the right and left of the trailer's lunette (the "O" portion that connects to the tow pintle). These chains keep the trailer attached to the prime mover in case the tow pintle's cotter pin fails (a semi-common occurance). The ends of the chains have a hook that attaches on the nearest secure point on the prime mover, normally the tow shackles, but sometimes on the tops of the bumperettes.

You can see the chains on this water buffalo from Prime Portal:

Just to be precise, the lines (electrical for lights) and air/hydraulic or vacuum/hydraulic, are part of the trailer and connect FROM the trailer TO the truck.

The original series trailers (M105A1 - Cargo and M107A1 - Water) had a single air/hydraulic brake line (in addition to the electrical connector), and according to the diagram in TM 9-2330-213-14&P, this connects to a fitting on the truck frame on the left vehicle side.

According to the TM, ALL trailers built after 1977 (certainly well after Vietnam) had two brake lines, and were either designated as M105A2/M107A2 for air/hydraulic OR in the case of the Cargo version, M105A2C which had two vacuum/hydraulic lines. In either case, the second line attached to the truck in the same location on the opposite side.

The TM also talks about an M107A2C, but curiously in ALL places it indicates that this version was AIR/hydraulic and NOT VACUUM/hydraulic like the cargo version. Doesn't seem right, but that's what is says.

I'm certain that the introduction of the two line versions at least BEGAN earlier than 1977, because I recall all our trailers in Germany (1972-1977) had two brake lines. I also seem to recall the two "glad hand" connectors for these air lines were color coded red and yellow on both the truck and trailer because it made a difference which way they were connected. You'll notice that the connector for the airline in Sabot's picture of the water buffalo is painted yellow.

My guess is that for a Vietnam War version a single line would be more appropriate.

One last minor detail. When you are hooking up the chains from the trailer to the two towing shackles on the truck, the TM indicates that they should cross, with the one connected to the left side of the trailer lunette connecting to the right vehicle side and vice versa.

I don't know if the PSM versions use actual chain instead of a "2-D" PE. If you're using actual chain, my method is to use thread to connect the last chain link to the eye under the draw bar.

Tom

we used a different water tank than the one in the picture. The tank was longer, but also lower in higth. It was also oval shaped. I also donot remember the third wheel on it like the photos show, and I should because we made a water run with it almost daily down on Gator. The big flat bed trailer was just like the one we had, but of course a different color. I only saw it in use a couple times as it was assigned to the motor pool.
gary

I'm pretty sure you're talking about the M107 series water trailer. Earlier versions had a single large wheel on the adjustable caster assembly rather than the two smaller ones shown in Sabot's and Frenchy's pictures. The water trailer shown in Sabot's picture is an M149.

I just used the photo to show the safety chains, not to show a Vietnam era trailer. It is a later water buffalo. The older ones that we had when I came in had the fiberglass tank that was sort of oval. Sorry for the confusion.

Just a few period pics...

M107 water trailer :


M107s with fiberglass tank (I think ) .








Here's a better picture of the M105A2 caster folded up :





Frenchy

|
More surely M149 Trailer tank water

OOOOPS I stand corrected Pascal. Of course you're right Trailers nomenclature is a bit confusing...According to the TM that can be found here :
http://old.steelsoldiers.com/index.php?module=pagesetter&type=file&func=get&tid=1&fid=file&pid=26 ,
both the M149 and the M149A1 are fitted with a fiberglass tank. The M149A2 is fitted with a stainless steel one.

Frenchy

Yep....the 149 is firberglass as opposed to the older metal water buffalo.

Tom...I gave my last comments by memory.....now that you discuss the TM..thank god some one brought out the bible.....I think I do remember brake lines on either side plus electric....

As far as the chains....forgot to mention those...most US trailers of size have them....crossing the chains was a PITA. 99% of the time I remember the just being hooked up on each side!!

Rounds Complete!!

Which is misleading itself because when we had a fiberglass tank crack (the one with the flanges) and ordered a replacement, we got a stainless steel one to mount in its place. Visually, it now looked like an M149A2, but on the property books, it was still an M149A1.

There are some great replies to this thread.
I have the M149 with the "oval" shape body which, as I now understand it, is made of fibreglass.
So, let me get this straight. The securing chains are attached to the shackles that are located behind the bumperettes. Right?
If I am building a Vietnam dated trailer there should be only one cable. Correct? But where does it plug into on both the truck (which is an M35A1, in my case) & the trailer. Is it like in the photo above with the yellow connector? Where & which side of the truck?
Thanks fellas.
Joe.

that you are probably right about. The trailer was small enough to be airlifted out to FOB's, and held enough water to last about a day and a half. Maybe 200 gallons max. We also used blivits a lot, but the valves were always a problem (often they'd forget to send them out with the blivit!). Also a lot of companys had a dedicated water truck with a home built tank ontop. These were for non potable water supplies (showers, etc). Rarely was a unit afforded the luxery of a for real water tanker truck (if ever)
gary

the tanks we used were steel, and the insides were painted white just like Jerry cans were. The lid ontop was held in place by what seems like a latch, and it flipped up to one side. We would go thru the line at the pumping station and flush it out, and then get out of line and drain it. Then get back in line for a fill up. The valve was at the rear if I remember right. The water detail was a much sought after detail; as it got you within eyesite of the Americal main PX (we had a route we would run that took us to four or five PX's).

As for the third wheel, I'm gonna have to look thru some pics again. I just remember it being blocked up with ammo pallots at the tongue right outside the mess hall (perhaps the third wheel was damaged?). The trailer balanced very well when full of water, so two guys could unhook it from the pental without much effort.

Back to the box trailer a second; I remember a 105 unit (maybe 6/11th) that used to get ammo resupplies loaded in those trailers. They would fly it out loaded, and then they hitch it up to a truck and haul it away (probably four or five trailers were in use). Never work with a 155 or 8" unit due to the weight factor alone, and everybody had their own way of doing things.
gary

Only in the Army!

was the stainless steel tank painted on the inside?
gary

Joe
Here's a TM close up of the M35A1 trailer air couplings, located on the rear of the truck on either side :


You can see the right one just below the rear light cluster :


Here's another TM drawing showing the air hoses on a M105A2C trailer. For a Vietnam era trailer, I think only the service air hose (#2) would be present.




Frenchy

The line drawing from the TM that Frenchy included should show you pretty much all you need. As he stated, the notes that accompany the drawing indicate that when you have a single air line (as with the earlier models), it's the one marked "2" in the drawing and would go on the left side.

What's confusing is that the drawing appears to show "quick connect" fittings, which would slide straight in. What we had were the "glad hand" connectors which you can see very nicely in the M35 illustration. The dummy connector was chained to the truck to seal the line. When hooking up a trailer, you gave that a quarter turn, and twisted it off and left it hanging. There was a similar fitting on the trailer air lines and those were installed with the same quarter turn. On the M35, they were on the outside rear of the frame rail as shown in the second illustration. The actual truck air lines ran on the inside of the frame rail up to the vacuum/booster up in the engine compartment.

And as I mentioned they were color coded with red on one side and yellow on the other. Naturally I can't remember which was which, but I'm sure somebody out there knows. I suspect from the picture Frenchy has that the yellow was on the LEFT vehicle side. You can clearly see the yellow connector in his picture, but when stowed on the trailer, because they need to be long enough to connect to the trailer, the hoses are crossed. The line to that connector actually runs down the LEFT frame rail of the trailer. You can barely make out the RH side one behind it, and it crosses over and is no doubt connected with a red glad hand on the other side of the trailer behind the caster. However, I'm pretty sure that when you hook the lines up, the one running down the left trailer frame rail (yellow) goes straight forward to the fitting on the truck without crossing, making the fitting on the left side of the truck yellow as well.

Also his first picture gives you a pretty good picture of the older style single wheel caster which might have been more likely to have been on the Vietnam era trailers, but I DOUBT anyone will notice.

As I said, I'm pretty sure we had two lines as early as the mid-70's in Germany, but it's probable the equipment in Vietnam may have only had one.

While I'm pretty certain the single line connected on the left side, what I DON'T know is whether it was color coded. Most likely NOT since there was only one hook up.

I believe that more than one configurations can be found...Here's a 1968 M105A2 with single wheel caster and dual air hoses (built by Johnston Corp. in September* ) :


and another 1968 one (built by Johnston Corp. in February* ) with dual wheels caster !



*according to the data plates visible here : http://militarytrucks.com/1.5trailers.html


Frenchy

Actually there is only one air line in the first picture. It runs down the right side and is stowed with a mount on top to keep dirt out of the air line. The black cable on the left side is the electric hook up. It runs down the frame rail and also doubles back and the plug is held in place with a clip. This is the large balck thing on the top of the right frame rail. Here are some close up pics of one of my trailers that I took when I picked it up a few years ago. It's also a 1968 trailer.

Service air mount

Electrical plug and clip


Where the lines double back to the stowed mounts

Thanks for the clarification Dave (and thanks for the pics too) !

Frenchy

No, it was unpainted stainless steel inside. I do not know if there was some sort of clear coat or just plain stainless steel.

Dave’s last picture is a very good one to show how the caster assembly works. The entire caster assembly is hinged so that it lifts up around that large piece between the trailer arms with the two holes and the bolt. Once the circular lunette on the trailer draw bar has been placed and secured on the truck’s towing pintle, the assembly is rotated up 90 degrees between the trailer arms and secured in place by inserting the handle (just barely visible off to the right) into the two holes.

Then just before you disconnect the trailer from the prime mover, you pull on the handle (I believe it’s spring loaded to the “in” position), lower the assembly to the ground and re-secure it in the down position. Now the entire caster assembly with the wheel (or wheels) can rotated 360 degrees around that bolt.