Bingo - I had the same thought. A friend gave me a complete freight HEMTT kit that I thought I would use the newer chassis and tires on. I have always wanted to build that somewhat freaky (to me anyway) crane that comes in the kit.

Gino I saw recently a HEMTT model where the crane was mounted directly behind the engine. Was that one of yours? What was the prototype?

I would love to build a HEMTT A3 using this spare chassis but I just don't think my wallet is up to buying two more Mk23's to get the necessary TAK-4 suspension/drive units.

The only HEMTT type I know of where the MHC (Material Handling Crane) is directly behind the engine is the M1074 PLS. It is used by artillery units as an ammo truck and the MHC is used to unload or move the ammo around.

M1074


My M1074 model

Gino, I was afraid you would say something like that.

That's a great PLS you've got there!

Mike,

Here's an 8x8 HEMMT PLS with crane. Hope this helps.

https://www.youtube.com/watch?v=LR0q6MykzHk

I guess some versions of the M1120 LHS also have the MHC behind the engine (as in the above link and below pic).


Based on the door marking (112 in a dashed square), they may be the same truck. I am not sure if this is an operational or test vehicle just for the bridging system.

This experimental bridge system M1120 also has the MHC behind the engine.


It looks as if the Multi-Lift rack is slid further back and has a rear chassis extension to fit the MHC in that location.

I can't seem to find any other HEMTTs w/the MHC behind the engine. I think this is just part of the experimental bridge system that is being offered.

Well that gives me a few options. Thanks guys.

It is very interesting that even carrying the crane AND a full sized LHS and flatrack this HEMTT is built on the shorter semi-tractor frame!

Working more on the LHS:






I chose to model the LHS "hook" in the stowed, travel position. As currently built the hook is still positionable and all it takes is to insert a small rod into the locking hole to make it immovable and functional again.

Also shown above (lower right) is the door mounted shipping placard for the HEMTT LHS that illustrates how the vehicle overall dimensions are reduced when transporting by air or by rail.

The M1120 is actually built on a slightly shortened (by only 6 inches) M977 HEMTT frame. The M983 tractor frame is 29 feet, 6 inches. The M1120 frame is 33 feet, 6 inches. The M977 is 34 feet long.

I was judging by how close the tires are to the gas tank AND with no tool box on that side, I thought it was a much shorter vehicle.

The crane actually takes up quite a bit of space, that is why there is no tool box and the tires look closer.

Yes, I see now that the crane stabilizer legs take the place of the toolbox in front of the gas tank.

Is the six inches you spoke of taken out of the frame just ahead of the rear wheels? (Of course on the real thing they don't "take it out" they just build it shorter in the first place.)

Yes, it appears all frame length adjustments are just forward of the rear wheels.

Thanks - good to know.

Revisiting an older question:

What is the purpose of this structure?


It has been said to be a frame strengthener which I do think is one of the functions of the brace on this extremely long framed vehicle. However it also occurred to me that without these bars on each side in this area, the driveshaft would be totally exposed to any sort of "over-center", high ground point collision. So perhaps these also function as a protective device for the driveshaft.


(Photo by halftrack - www.steelsoldiers.com; used here for discussion purposes only.)

Interesting winch mounting on the long frame Mk28 MTVR. (Shown here on the passenger side, rear corner of the vehicle.)


(Photo by halftrack - www.steelsoldiers.com; used here for discussion purposes only.)

The Italeri model is constructed almost exactly like the actual MULTILIFT LHS so that the hook can be folded down if desired, however no indication is given of this very possible option in the the instructions.


Please Note: This lifting hook conversion does require the drilling of one hole through the main hook portion of the arm.

Perhaps those are torsion bars?

Yup torsion bars.

I confirmed this with my buddy that works at Ft. Sill.

Dustin can you get any further technical documentation out of your friend? In the photo we can see the coil springs in the axle behind these bars so I assume they are not connected there and they seem like they are a bit long to be supporting the front axle.

My first thought also was that they were torsion bars but so far I have no other source to say this is the case.

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Inquiring minds want to know - and also because I don't just need to know it - I need to build it!

If someone would just offer a resin engine for the Mk23 I would probably have to build a third one of these trucks. Maybe the extended frame, long load bed version.

I am still trying to research the structure that seems to be added just ahead of the #2 axle on any/all the longer MTVR vehicles that are based of the extended frame vehicle. At this point my vote is still leaning towards a frame stiffener but I am open to it being a torsion bar assembly or some sort of underbody protective device.



Here is a photo of an extended frame Mk 28 with the device. In the photo you can clearly see that both the front and #2 axles still have their coil springs. I am not for sure but I think that precludes those rods being torsion bars for the suspension.

It's definitely a torsion bar. The cad picture illustrates it fairly well, even tho we aren't seeing it from the other end.

I don't think it is the same structure as shown in the CAD. If it is, the bars themselves would have to go all the way up to the front suspension as the rear part on the truck is the bracket that attaches to the frame. I think the front has a similar bracket and it's purpose is to add stiffness to the frame to keep it from buckling or twisting under load.