HEMTT Material Handling Crane Curiosity - Steel Soldiers::Military Vehicles Supersite

nf6x · 07-28-2008, 23:51

Hey, everybody. I've been distracted by a home construction project for a quite a long time, and I've been ignoring this board and my trucks. My project and my move are still in progress, but things are winding down to where I can start to think about starting to think about trucks again someday!

So, after various headaches I swore off even looking at the GL web site long ago. Well, this weekend I had a weak moment, I looked at the current GL listings, and danged if something didn't catch my eye!

I've always really liked what Bjorn did with his crane truck, and I've often considered that if I ever had the gumption and money to put a nice knuckleboom onto a 900-series cargo truck, I'd get rid of my tired, old M543A2 wrecker and my last remaining deuce (an M35A2C), and be happy. I never take any of them on the road, anyway, and I just use my wrecker as a yard crane. I'd like it better as a crane if I could control it remotely and the outriggers were power-operated.

Well, it turns out that a big pile of HEMTT rear-halves are coming up for auction real soon, and a bunch of them are not too far from me. So, I'm eyeing those hydraulic cranes mounted on their rear ends, and coming dangerously close to drooling!

Those HEMTT cranes look kinda like the illegitimate offspring of a regular crane and a knuckleboom to me.

So, here I am now, wondering if any of y'all have experience with the HEMTT material handling cranes, and would like to comment on them:

How suitable would one of them be for a behind-the-cab installation on 2.5-ton or 5-ton 6x6, much like Bjorn did? Are they made to straddle a pair of frame rails like a common (?) knuckleboom, or do they bolt onto the HEMTT's butt in a way that wouldn't lend itself to mounting in the middle of a regular 6x6 chassis?

In terms of usability and versatility, how do these cranes compare to either regular hydraulic cranes like the one on my 5-ton wrecker, or a typical knuckleboom?

How do these cranes receive their power? I.e., would there be an electric pump mounted somewhere near them on the trailer, or would they just have a hose pair ran up to a PTO-driven pump on the (missing) tractor end of the truck?

The listings vary between two different NSNs for the trailer assembly. Some of them are listed as having "Wajax boom", and the other are listed as having "Pietzsch boom". I can see visual differences between the two kinds of cranes, and I wonder whether one kind or the other might be better for my hare-brained Frankentruck idea. The pictures of at least one of the Pietzsch ones show a Grove dataplate on the crane. I'd welcome any information or opinions about how these two kinds of crane compare to each other.

It's been so long since I've been active on Steel Soldiers, that I don't recall the consensus regarding posting links to auction listings. I'll just attach some representative pictures of the two kinds of trailer/crane here for discussion purposes.

I'm tempted to go take a good, close look at these cranes. If I did manage to win one, I'd also consider dropping the crane onto my M35A2C's chassis, since a nice 900-series truck ain't cheap!

Thanks in advance for any comments!

gimpyrobb · 07-29-2008, 00:00

Tom (spicergear) put one on his deuce.

wreckerman893 · 07-29-2008, 00:20

I would cut the arse end off of a 800 series truck and mate the front of it to that whole rig. What a hoss that would make.

Jones · 07-29-2008, 00:21

Those are actually the back halves of USMC LVSs.
You have two different cranes shown in the pictures. The first crane is a knuckle crane built under Palfinger license and looks bigger than the MHC977 as used on the HEMTTs-- even bigger than the crane used on the M985s. You might want to do some checking on weights before you overload the deuce and end up with a sway-back frame. A 5 ton might handle it better.
The second is a folding (scissor?) crane by Grove like the M985 HEMTTs have.
The HEMTTS (and possibly the LVSs too) use extensions that bolt to the outside of the stock frame rails and the crane and outriggers in turn bolt to them. I'm putting an MHC977 on the back of my baby HEMTT and will be posting pictures in a few days of the extensions I'm making.
PM me and I can give you more detailed info.

nf6x · 07-29-2008, 00:29

Quote:

Originally Posted by wreckerman893

I would cut the arse end off of a 800 series truck and mate the front of it to that whole rig. What a hoss that would make.

Well, if I win one of these suckers, I'll make you a sweet deal on the trailer after I pull off the crane!

cranetruck · 07-29-2008, 08:36

Quote:

Originally Posted by Jones

......You might want to do some checking on weights before you overload the deuce and end up with a sway-back frame. A 5 ton might handle it better.
.... .

This has been brought up a couple of times as a drawback for the behind-the-cab mounted K-boom crane....I have not had a problem with this after 13 years of experience with this particular crane use.
99% of the time my boom is extended over the bed for better load distribution.
Having a forward mounted crane is an advantage on a trail, since I can clear it in front as I go, fallen trees or a stuck vehicle in front for example.
A rear mounted crane will also limit the bed capacity when hauling long beams or logs.
A rear mounted crane may effect the capacity of the pintle (tongue weight) .
Any lift is done with the outriggers down, so no load is taken up by the frame.
A 4,000 lb crane mounted behind the rear axle will lighten the load on the front axle and may effect the steering.
Image #2 below shows minimum frame requirements for a 3,200 lb crane mounted behind the cab.
Images 3 and 4 are for the Autocrane A50A series and are close to the performance of my old HIAB...

dma251 · 07-29-2008, 10:33

hee hee.....

Here we go again!

cranetruck · 07-29-2008, 11:55

Hmmm...just providing info, the sway-back frame is a weak argument IMHO.
A 4,000 lb crane is not going to have the same effect(s) on a 10-ton truck as it will on a 2-1/2 ton one, so I'm only presenting some facts.

Elwenil · 07-29-2008, 12:28

I wonder what the Grove and Palfinger cranes weigh though. It's hard to tell by eye, but they seem to be a bit heavier than the average knuckle boom. Also, as Gimpy mentioned, Spicergear put a Grove behind the cab of his Deuce. As I recall he had to do a lot of modifications to the outrigger system and the crane base to get it to sit astride the Deuce frame. It also seemed to take up a bit more room on the frame than Bjorn's K-boom. There is a thread here on SS somewhere detailing Spicer's swap and modifications.

cranetruck · 07-29-2008, 12:44

I recall Leonard saying that the Grove crane is almost exactly the same weight as the K-boom on my deuce, 3,800 lb give or take.
That much weight centered about 3 ft behind the rear axle will lighten the front axle load by perhaps as much as 800 lb. I don't know the dimensions of the Baby hemtt, but it may have an adverse effect on the steering.