They Can't All Be Winners

A face that only a mother could love. Actually, although no one is sure, I think the above picture portrays the other end of the "Holt, 150-ton, Field Monitor" another of many failed First war tank designs.
No, it really didn't weigh that much. More like 17 tons.
One was produced, I assume at the Holt plant in Stockton, CA, shipped across the country to Aberdeen Proving Ground where it confidently rolled forth and got stuck after fifty feet or so, just like another giant, backward-tricycle tank, the Tsar.
What's cool about it was its propulsion system; steam.
I'm interested in the layout they used for their prototype too but for a different reason. More about that in a bit.
The big advantage of steam is this: Just like an electric motor, a steam engine has 100% of torque available instantly, at a dead-stop. No need for silly clutches and transmissions. Just turn it on and all the power goes to the wheels right now.
The downside of steam is that you can't just jump in it and go. The boiler's got to get up to pressure. In the case of the Union Pacific "Big Boys", largest locomotives ever built, warm-up ran around eight hours from a cold start. The Stanley Steamer auto, around seven minutes.
Both demand a certain level of deliberation.
With lots of jobs, that's not a problem. If you're going to be pulling freight trains for a while, an eight-hour prep, while inconvenient, isn't a giant problem.

Which leads me to what intrigues me about the layout of this thing.
Hell, I'll cut to the chase: It's nothing but a backward road-roller ("Steam roller" actually).
Well, it was a bit more than that.
The Holt used two kerosene-fired boilers, each powering a 75 HP Doble engine.
A separate boiler and engine per drive wheel to add power and a more nimble level control than was required for merely mashing pavement.
The entire thing was turned around to put the boilers in the rear out of harm's way and to put the big traction units, the eight-foot drive wheels out in front.
All for naught. As mentioned, it went fifty feet and got stuck.
It amazes me that anyone thought it would work.
But, unlike the Tsar, the Holt didn't break the bank and I'll wager was even built with stock parts. Ah well. Take it apart and make a roller out of it.
Holt was no dummy.
Besides, there are no rocks to throw at Holt regarding their wartime contributions.

Behold...
A pair of "Holt 75", artillery tractors, on the job in The Holy Land.
The Holt 75 provided the running gear for France's Char d' Assaut St. Chammond heavy tank and the Char Schneider CA1 medium tank.
I think, even the A7V was built on Holt-inspired tracks.
So we'll not go too hard on them for the funky, roller-conversion thing. They've paid their dues.
And speaking of rollers, what would you do if had one of them - but no steam engine to make it move - but you had a tractor - and some really big bicycle chains?
A fella in India did this:

My kinda guy!