M56 Scorpion, M50 Ontos, and all their derivatives, questions, and what-if ideas

[dy031101]

(M50 is based on the running gear of the Scorpion...... might as well include it and its derivatives in the topic in anyone has anything to say about the Ontos.)

I've always been under the impression that only the French tried the idea of rudder-tire road wheels on tracked vehicles post-WWII...... until I browsed Wikipedia entry for the M56 yesterday.

Curiosity here: does the M56 use any similar suspension like the Char Lorraine 40t or is the Scorpion just like any other conventional full-tracked vehicle, except only with rudder-tired road wheels?

Does the M56 have any derivative?  The Wikipedia doesn't list any other than those associated with the Ontos.

[jcf]

The M76 Otter also had a pneumatic-tired suspension, which didn't work out to well in combat areas.
You had the ludicrous situation of a tracked vehicle being rendered inoperative due to flat tires caused by shell fragments.

According to Hunnicutt Sheridan in Part IV: Specialized Light Combat Vehicles the M56 had a torsion bar suspension and the tires were normally inflated to 75 psi but could be run-flat for 15 miles at 15 miles per hour. The M56 was built by Cadillac.

As far as Ontos is concerned it was part of a separate family developed by Allis-Chalmers:
T55 Six-man and T56 Ten-man infantry tracked utility vehicles (only difference being length)
T164 Four recoilless rifles and machine gun (never built)
T165 Six recoilless rifles (Ontos)
T166 One reccoilless rifle (used ground mount)
T167 Eight recoilless rifles (never built)

A gasoline engine drove rubber band tracks and the vehicle had a 'torsilastic' suspension which used externally mounted rubber torsion bushings. Originally the vehicles had pneumatic tires, these were replaced with dual road-wheels with solid rubber tires.
Proposals on the basic vehicle included titanium armored assault vehicles (a titanium alloy upper hull armor shell was built) with
single or double  Quad - .30 turrets. A 75mm Pack Howitzer mounted on the Ontos chassis was also proposed.

The M56 and Ontos were not mechanically related.

[dy031101]

You had the ludicrous situation of a tracked vehicle being rendered inoperative due to flat tires caused by shell fragments.

Does it have more to do with the type of tires used (not being run-flat?) or is the suspension really to blame?

[jcf]

You had the ludicrous situation of a tracked vehicle being rendered inoperative due to flat tires caused by shell fragments.

Does it have more to do with the type of tires used (not being run-flat?) or is the suspension really to blame?

No it was the tires, it had a basic torsion-bar suspension, nothing exotic.