Removeable firebars - how neccessary are they?

[jma1009]

Hi Steve,

To get back to your original question, if you get the draughting right, the fire won't have to be torn to pieces at a higher rate of combustion otherwise required, and far less erosion of the grate.

Did I send you the smokebox re-draughting I did for Jim's Brit?

If it were me, I would get some tough stainless strip of say 3mm thickness some 9mm wide to make up the fire bars, with 6 or 8mm stainless rod spacers of say 4.5mm width drilled for 3mm stainless rods to join the sections together.

Cheers,

Julian

[springcrocus]

Julian,

As designed the firebars are actually a bit bigger than that. The spec is 1/2" x 1/8" mounted on 3/16" dia crossbars with 200 thou (approx) spacers from 3/8" dia material, all in stainless steel. Loads of bulk and, maybe, unlikely to burn through as long as the ash is kept under control.

There must be others who would like to offer an opinion? How many Brit owners, and there must be dozens of you, have ever had to replace the grate?

Regards, Steve

[don9f]

Hi Steve, I’m not a Britannia owner etc. but the dimensions spec. you mentioned above is exactly the same for the Les Warnett 9F. Unlike the real thing, mine hasn’t got functional side doors in the ashpan for clearing the very shallow sloping areas just under the outside parts of the grate, where they are above the frames. The hopper on a 9F is completely inside the frames, so it’s a totally different ashpan to the Brit. Cleaning the areas mentioned could only be done once the grate sections were lifted out. Your hoppers are much better at keeping ash clear of the bars.

Bearing this in mind, in the seven years of hard running the engine did before becoming “stored out of use”, the grate has not suffered at all and to this day is still in mint condition. I don’t know what grade the stainless was, but the stuff I bought just a few weeks ago for the 3F is 3mm x 12mm and looks exactly the same material.

I don’t believe you are going to have a problem with the grate burning away and would suggest that if you can, arrange for the centre sections at least, to be removable through the firehole for disposal at the end of running etc. and don’t bother with pivoting bits.

Hope that helps Don

[coniston]

Hi Steve, I've held off commenting on this thread until I had a chance to chat with a fellow Fareham club member who has been running a 5" Britannia for many years. His grate is in 4 pieces and removable through the Firehole door. The pieces have to go in the right place as each are slightly different, so are marked with notches 1 to 4 to ensure this happens. His fire bars are stainless of 1/16th thickness by 1/2" depth. Gap is between 5/32 for the outside pieces and 1/4 for the inner ones. He did say that he spends considerable time once they are removed to clean any remaining coal and ash with a vacuum cleaner with suitable home made attachments to reach all round inside before the bars are replaced.

Hope this helps

Chris D

[delaplume]

Hello all,

Have a look at the early part of this Silvercrest training video for a 9F..........It shows the 3-part grate being fitted.....One video is worth a 1,000 words so to speak............go to 050.00

youtu.be/3alISY7ADik

[ettingtonliam]

Interesting.Questions for the experts:-
There was no mention of any locking device on the tender/engine coupling pin.
That injector seemed to dribble all the time it was working -is this right?
The drain cocks were blowing when the engine was running, maybe this was intentional?
Mention of doors to empty the ashpan but no mention of dam,per control, or are these the same thing?
Finally, is it my imagination, or was the blow down cock blowing out sideways instead of downwards? Isn't that a hazard?

[delaplume]

Hi,

Normally the fall plate doesn't have that big hole in it and when down flat acts as a stop against the pin moving upwards.....

Ideally an injector will run without any dribble but sometimes it can't be helped.....Personally I prefer to open the steam valve "smartly" and fully, then adjust the water valve to suit ( Full size or model )....Remember that your injector is a "Heat Difference" device and you should always endevour to keep the feedwater cool or cold...

Drain cocks should be closed as soon as possible after starting providing that all condensate has been removed......In this case I think he just forgot to as the loco wasn't going anywhere..It's normally part of your departure routine only in this case he wasn't going anywhere...

Generally speaking on the smaller gauges you don't often find actual dampers per se fitted......But then the full size ashpans are nothing like those on the smaller gauges either..

Yes, that centre-fitted blowdown valve did appear to be discharging sideways, didn't it ??.........It should be routed down and between the frames, in the same way as the gauge glass one is..

I hope that's of some help ??

PS}---- In the film he advises that the Engine Steam Oil should be of a "Heavyweight".....That's only needed with high degree of superheat, otherwise the lightweight should be suitable...
also that for the rest of the oil points "any heavy oil will do, even a motor oil"....Recently I've use an EP oil which seems to work ok, but it's been suggested to me that Buzz-Saw chain oil might be of use as it's specifically designed to be Anti-fling.......I'll be trying some of that this coming season...Steam oil may seem thick when cold but soon thins out when heated....

[don9f]

In the film, reference to the “Ash Doors” at the bottom of the ashpan hopper, means that Silvercrest have replicated the arrangement of a full size 9F that has two such doors, one in front and one behind the rear driving axle.. These would normally be closed until disposal at the end of the working day, when they would be opened to dump the ashpan contents into the pit.

There was no mention of “Damper Doors” on the model, again of which a full size 9F has two, one front and one rear of the upper part of the ashpan hoppers, much nearer the grate. These are controlled by hand wheels on the fireman’s side.....so not the same as he was talking about in the film.

Cheers Don