[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: Advice and a New Paper



On Fri, Oct 16th, 2009 at 9:34 AM, David Marjanovic <david.marjanovic@gmx.at> 
wrote:

> >  By contrast, "Locomotives weigh anywhere from 120 to 240 tons each,
> >  depending on the size. Mainline units are the heaviest, switcher
> >  units and yard engines are the lightest.
> >
> >  "Rail cars can weigh anywhere from 30 tons (empty) to 140 tons
> >  (loaded) each. Special cars designed to carry extra heavy loads can
> >  weigh well in excess of 200 ton"
> >  (http://answers.yahoo.com/question/index?qid=20061007151346AAWdaRL)
> >
> >  Now, you can hear and FEEL them things coming - and they don't even
> >  walk!
> 
> Maybe that's because they don't tread lightly. They roll at enormous 
> speeds and thus make a little jump at every tiny unevenness of the road 
> or rails.

Trains also 'locomote' on rigid steel wheels contacting rigid steel rails, with 
a very small area of 
contact between the two (as would be expected of any circle touching a plane). 
By contrast, 
sauropods locomoted on fleshy feet, with a very broad area of contact with the 
ground. 

Elephants are very careful of exactly how they take each step, since to trip or 
lose balance could 
be fatal. I suspect sauropods would have been even more careful about foot 
placement. If a 
diplodocid tripped with one of it's forefeet and went down, chances are the 
neck would crash 
painfully into the ground before they were able to react and recover. Ouch.

I imagine that if a sauropod was to sneak up behind you on hard open ground, 
you'd probably hear 
them breathing before you heard a footstep (especially since their head would 
reach you long 
before their feet were anywhere near you). Digestive rumblings (or emissions) 
might also have 
been more audible than their footfalls (unless of course they happened to step 
on the 
ubiquitous 'breaking twig', that has been the downfall of many a movie 
hero/villain).

-- 
_____________________________________________________________

Dann Pigdon
GIS / Archaeologist                Australian Dinosaurs
Melbourne, Australia               http://home.alphalink.com.au/~dannj
_____________________________________________________________