Jump to content
 
  • entries
    122
  • comments
    870
  • views
    104,176

Through a Time-Warp


MikeOxon

1,055 views

I've mentioned before that one of the reasons why I like to model unusual prototypes is so that I can compare them with more familiar stock. Here's an example:

 

blogentry-19820-0-42134200-1411055943.jpg

 

The Dean 4-2-4T was built around 1881, to explore the idea of a high-speed express tank locomotive for use when the broad gauge became extinct. It failed because of a severe tendency to de-rail, probably from poor bogie design, coupled with the large amount of water sloshing to and fro' in the long side tanks.

 

In comparison, the Collett 'Large prairie' (Dapol/Airfix kit), of which the prototype was built in 1935 for fast suburban services, has very similar overall length. The side tanks are both shorter and taller, which should help weight distribution and, of course, with six coupled wheels, adhesion is much greater.

 

I find it interesting to be able to visualise the similarities and differences between these two designs from 75 years apart!

 

Mike

  • Like 6

7 Comments


Recommended Comments

Wow, what a fascinating engine! I guess there weren't any baffles in the side tanks of the 4-2-4T at that sort of date which wouldn't have helped with stability, and as you say, that's an awful lot of water sloshing around in there - almost tidal surges ;)

 

Perhaps not one of Dean's most elegant designs either...

Link to comment

Thank you, Buckjumper - the engine has intrigued me for a long time! 

 

I should emphasise that the model is my own interpretation of what little information is available, so any inelegance may not be down to Dean  :)

 

Mike

Link to comment
  • RMweb Gold

It is funny but the county tanks seem to have been rough riders whereas the prairies were very successful. I have a recollection that they were intended for frieght originally by Churchward but later became used for passenger work.

Don

Link to comment
  • RMweb Gold

I know which one I'd rather ride behind in terms of safety - but the other one I really like the look of. I've been trying to think what it reminded me of, and now I've realized it looks like something Jules Verne would have come up with!

Link to comment

Safety seems to have been viewed very differently in the 19th century, Mikkel.  The thought of all those early GWR engines dashing around at 60+ mph, with virtually no brakes, is quite terrifying.  I have an ancestor, who was repeatedly reprimanded for over-running stations and it is easy to see why!

 

Thank you Job. I'm pleased that you also find it interesting.  Nowadays, we test ideas with computer simulations, so we never see many of the failed experiments.  The rather square lines of those early tanks do , however, remind me of modern power cars.

 

Some experiments were a lot wilder than these - see https://www.rmweb.co.uk/community/index.php?/topic/14790-imaginary-locomotives/&do=findComment&comment=1573977

 

Mike

Edited by MikeOxon
Link to comment

It is funny but the county tanks seem to have been rough riders whereas the prairies were very successful. I have a recollection that they were intended for frieght originally by Churchward but later became used for passenger work.

Don

I suspect that the longer coupled wheelbase was a big factor in the case of the Prairies.  By many accounts, the 4-2-4T had very little lateral stability at all :)

Link to comment

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×
×
  • Create New...