Coal pile height

[Rabs]

Simple question I hope: How high could the coal be piled in the rear bunker of a tank loco? Specifically a small tank like a gwr metro or 14xx?

 

I've seen modest piles, such as in this model here:

http://www.bandhmodels.com/index.php?main_page=product_info&cPath=1_2_30&products_id=4773

 

I'm currently designing a small tank loco (GWR metro tank) to scratchbuild in N gauge. I'm trying to find space for a dcc decoder, and the most promising location is upright in the bunker. However, with the decoder that I have in mind it protrudes a little out of the top. I'm hoping to cover this with coal, but I want to check that the height that I'd need wouldn't be silly and unprototypical.

[chaz]

I think the answer has to be......it depends. On what? Well, how long a shift is the loco going to do? How much work has the loco done since it was last coaled? I don't know much about the GWR but I can tell you that some classes of LNER tank locos were fitted with coal rails so they obviously didn't carry sufficient coal as-built. So you could expect those to be carrying as much coal as they could get on. Water could also be a problem (although less obvious on a model). When the preserved GNR saddle tank was used on specials in the sixties water was the problem. When it worked on a special south of the Thames (here there be dragons!) I seem to recall that it had to stop about every 40 miles for water.

 

My best suggestion is find some pictures of the loco you are modelling and follow what you see....

 

I know it doesn't help you at all but when the Pacifics were working the the non-stop out of King's Cross they packed as much coal as they possibly could onto the tenders. I understand that a platform gate at Hatfield, adjacent to the down fast, was sometimes smashed by lumps of falling coal dislodged by a lurch on the sharpish curve into the station. Scary stuff!

 

Chaz

[Xerces Fobe2]

Maybe another DCC option possibility - the level of coal in the tender/bunker reduces as the loco travels around a layout!

 

XF

[Miss Prism]

Tank engine bunkers tended not to be filled too high, if only to preserve reasonable visibility and to prevent too much coal dust getting to the crew when running backwards. For open-cabbed tanks, like an early Metro, coal in overfull bunkers would spill too much. (Tank engines tended to bounce around a bit.)

 

Edit: For a Metro tank, you'll need all the space you can at the rear end for weight, so a chip in the bunker is probably not the best place. For a 14xx, the converse applies!