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Post Info TOPIC: Speed Of The Skeleton Tank.

Speed Of The Skeleton Tank.
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Every tank of WWI had a different engine efficiency rating. This was due to the fact that all transmissions lose a bit of energy from the engine, when they supply power to the tracks.

So I have created a table listing the efficiency of selected AFVs of WWI. I list this efficiency as MPHpHPpT, Miles Per Hour, per Horse Power per Ton.

British Mk.V
150 hp. 5.17 Horsepower Per Ton. 29 tons. Max Speed - 4.6 mph. 0.8897 mphphpt.

Ranault FT-17.
35 hp. 5.38 Horsepower Per Ton. 6.5 tons. Max Speed - 4.8 mph. 0.8921 mphphpt.

Schneider CA.1.
55 hp. 4.07 Horsepower Per Ton. 13.5 tons. Max Speed - 3.7 mph. 0.909 mphphpt.

Saint Chamond.
90 hp. 3.9 Horsepower Per Ton. 23 tons. Max Speed - 5.3 mph. 1.35897 mphphpt.

90 hp. 6.4 Horsepower Per Ton. 14 tons. Max Speed - 8.3 mph. 1.2968 mphphpt.

200 hp. 3.75 Horsepower Per Ton. 30 tons. Max Speed - 8 mph. 1.2 mphphpt.

60 hp. 8.708 Horsepower Per Ton. 6.89 tons. Max Speed - 7.5 mph. 0.8612769 mphphpt.

150 hp. 7.5 Horsepower Per Ton. 20 tons. Max Speed - 7.9 mph. 1.05333 mphphpt.

Fiat 2000.
240 hp. 6 Horsepower Per Ton. 40 tons. Max Speed - 4.5 mph. 0.75 mphphpt.

Horsepower Per Ton: Divide 'HP' by 'tons'
Mph Per HP Per Ton: Divide 'MPH' 'by HP Per Ton'.
Using Average MPH Per HP Per Ton to find top speed: Times 'Average MPHpHPpT' by 'HP Per Ton'.

And here is the problem folks, if you go by what popular books tell you, this is the efficiency of the Skeleton Tank:

Skeleton Tank
100 hp. 11.11 Horsepower Per Ton. 9 tons. Max Speed - 5 mph. 0.45 mphphpt

5mph? 0.45 MPHpHPpT? That would make it the most inneficient tank of the entire war.

However, if you take an average Mph per HP per Ton, of my selection of tanks in WWI, you are including designs that maybe had great transmissions, and designs that had absolutely horrid transmissions. And the Mph per HP per Ton is the -efficiency- of the entire design, speed wise.

The Mph per HP per Ton ranged from .75 Mph per HP per Ton (Fiat 2000), to the 1.35 Mph per HP per Ton of of the St. Chamond. With most tanks having an efficiency of close to 1.

The worst transmission apparently, was the Fiat 2000. With its transmission, the Skeleton Tank would only go at 8.3 mph. However, I guess despite all its horrible failings, the St. Chamond actually had a fairly good transmission. If the Skeleton Tank was fitted with that transmission, it would have reached almost exactly 15 mph. The speed a worker from the Pioneer Tractor Co. said the Skeleton Tank could attain was 10-15 mph. So, this is totally acceptable.

However, if you take all extremes, 9 diverse tanks from WWI, the average Mphphppt is 1.02 , and even with this the Skeleton Tank would have had a speed of 11.37 mph.

Think of this, if you go by what the books say, that the Skeleton Tank could only go a measly 5mph, despite the original creators of it saying otherwise, this would give it a Mphphppt of .45 , the absolute lowest of any AFV in WWI. The oddity of that, coupled with statements from the original creators placing its speed between 10-15 mph, strongly suggest that the published information is FALSE. Perhap they forgot a 1 in front of that 5.

Check my math.

--Average MPHpHPpT of Selected Tanks--
0.8897 mphphppt.
0.8921 mphphppt.
0.909 mphphppt.
1.35897 mphphppt.
1.2968 mphphppt.
1.2 mphphppt.
0.8612769 mphphppt.
1.05333 mphphppt.
0.75 mphphppt.

10.1444769 / 9 = 1.0234641

Average Efficiency Of Selected WWI Tanks: 1.0234641 MPHpHPpT.

Speed of Skeleton Tank if transmission had average efficiency: 11.37 Mph.

Conclusion: The 5mph speed that all popular publications list for the Skeleton Tank is COMPLETELY wrong. In all reality, the speed was between 10 and 15 mph, probably towards the high end of that range.

This is important, because the Skeleton Tank is one of the most under acknowledged tanks in history. Setting the facts straight, that this was a FAST tank, is greatly needed. Because of its speed, coupled with its inventive design, it could have made a GREAT name for itself on the WWI battlefield.

I know the math is a bit tedious and complicated, but if you fully understand my reasoning you will agree with my conclusions.

Dont you ?

Roger Todd

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I understand your reasoning, I have no problem with that, but without hard data for the transmission of the Skeleton Tank, it’s hard to draw any solid conclusions. Maybe it really did have a diabolically bad transmission? Perhaps, say, the pipe-work body flexed too much, thus losing a lot of power to the sprockets?


As you point out, it should have gone faster, as the article on this very site says that…


The engines, two Beaver four-cylinder with forced water cooling, total h.p. 100, [gave] it a quite satisfactory ratio of 11 horsepower units per ton, which was more than double that enjoyed by the British Mk V, which only sported 5 hp per ton…


But even with that handicap, seeing as the company that designed it was awarded a contract for a thousand, it must have pleased a fair few people who counted!


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Yes, it could have had a diabolically bad transmission.

But is there more evidence saying that the stated speed of 5mph is right, or wrong?

I use my calculations of efficiency to show that the top speed of 5mph would mean the Skeleton Tank simply had one of the worst transmissions ever fitted to an AFV. This seems unlikely.

Couple that, with a quote made by George K. West, an Officer of the Pioneer Tractor Co. of Winona Minnesota that built the damned thing, who said the Skeleton Tank was a “war tank with a powerful gasoline engine and top speed of 10-15 mph,”.

I think there is more evidence to suggest the 5mph number is wrong, rather than correct.


Roger Todd

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More research definitely needs to be done, research into primary sources.

However, I'd not be too quick to give the manufacturer any more credence than other sources - after all, he's trying to sell the thing!

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