Re: Strategic Reserve.

[dave pierson <pierson@mail.dec.com>]

Michael Walker wrote:
 
> > Well, someone needed to invent the tank first.  8)>>
> > (If anyone asks, I'll explain the link between railroads and the
> > invention of the tank...)
 
> OK, I'll be the mug...

	Once Upon a Time...

	Actually ca 1900, or a bit before, in California, US of A, there was
	some good farmable land, EXCEPT it was too soft for horses, or
	existing wheeled steam (or gasoline...) 'traction engines'.  Someone
	(maybe Holt, I'd need to go to references..), came up with a
	'track laying engine'.  This gem of baroque mechanism, was modelled
	on RR practice, with 'ties' to spread the weight, and 'rails' to
	transfer the drive.  The rails were segmented, rougly 6" long, owing
	much to linked chain.  The machine literally laid down track ahead
	track ahead of itself, and picked it up behind, in a continuous loop.

	The original incarnation had full length ties, say 8 ft or so long,
	carried on a cage over the top, with the engine/boiler/operator
	in between (cf the British Mark 1-IV series of WWI, tho they
	arrived at the arrangment independently. [1]).  The sectionalized track
	was picked and laid down and routed over the top of the vehicle.
	Hence 'track laying' or 'tracked' vehicle.  Speed was slow,
	steering was uhhhhhh, intriguing.  But it worked, and opened huge
	areas to cultivation.

	It was rapidly found that the 'ties' could be a LOT shorter,
	shrinking to the length & width of the modern 'treads' of a classic
	'Caterpillar' or tank proportions.  (tho those vary to suit...)
	The residual rail remains in the guide ridge or ridges inside the
	track.  Once the ties no longer had to be continuous, it was easier
	to adopt the modern arrangement of running the tracks more or less
	under (actually along side) the body of the vehicle...

	Most books on AFV development go only back to  '...they saw Holt
	tractors moving guns and ...', occaisionally one will go back
	and explain where the Holt's came from...

=============
[1]
The shape of the Mark 1-IV is dictated by the need to cross trenches. 
They
nosed DOWN, so having the track all up the front helped them climb UP. 
This
lead to the track routing over the top.  Those familiar with the
unditching
beams of WWI usage will see further correlation to the _track_ laying
ancestry.  The decline in the use of trenches, and improvements in
weight distribution of later tanks made 'over the top' treads
obsolete...


	best
	dave p