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Locomotive Temperatures

Posted: Fri Sep 26, 2014 8:12 am
by Alan P
Don’t know if anyone will be interested in this but anyway………

Ok, whilst not a model this is about a live steam locomotive, just that the scale is 1:1.
I had the good fortune to visit The Launceston Steam Railway early in the week and took an infra-red digital thermometer with me. I bought the thermometer to use on my model steam engines but thought it would be interesting to see how hot the real thing got. The locomotive running on the day I was there was the Port Class Quarry Hunslet Lilian. Measurements were taken of the firebox and the smokebox, Kay Bowman kindly pointed out the hot spots on the firebox and these were used to take the smokebox readings.

With the locomotive stationary waiting to take the first train of the day the temperatures were as follows,

Smokebox 75°C

Firebox 171°C

The run to Newmills is slightly uphill, maximum gradient is 1 in 80 and the loco runs tender first in reverse, the temperatures were taken again,

Smokebox 240°C

Firebox 179°C

Posted: Fri Sep 26, 2014 10:09 am
by DolwyddelanLightRail
Id be quite interested to see that on other narrow gauge locos that have to work pretty hard (like Linda and Blanche) and see what the differences are. Be also quite interesting to see in action on 16mm locos as well with a different fuel types.

Posted: Fri Sep 26, 2014 10:29 am
by steamie1
Interesting stuff. I'd like to know.

Posted: Fri Sep 26, 2014 10:45 am
by Big Jim
Didn't the fr have problems with the alco's smokebox temperature when they first converted to oil firing?

Posted: Fri Sep 26, 2014 4:39 pm
by AFGadd
Big Jim:104365 wrote:Didn't the fr have problems with the alco's  smokebox temperature when they first converted to oil firing?
The Ffestiniog had many issues when they converted the fleet to burn oil, not least of which was actually getting the system to work...

When they did get it to work they had real problems with the paint burning off Linda, Blanche & Mountaineer's smoke boxes, such was the temperature now being reached by oil burning.
The double engines did not suffer because they are never driven quite as hard.
The short term solution was to paint the boxes silver, the long tem was to find a high temp black paint. Which they eventually did after searching worldwide, only to find a manufacturer in North Wales...

Incidentally, the reason that burning oil causes different issues to coal is because most of the heat created from burning oil is transferred in the tubes. Unlike coal where most of the heat is transferred in the firebox.

Another addition fact:- The above is why the FR also had such incredible results with super-heating as they converted to oil burning. The temperature around the super-heater elements being much greater than can ever achieved by coal.

Posted: Fri Sep 26, 2014 11:45 pm
by DolwyddelanLightRail
The double engines (bar DLG) never worked well on oil in the first place, from the stories I've been told on the Meld and Square it used to be ramp it up leaving port and hope for the best. DLG is that powerful it never needs to go out of pilot valve hence for not being driven hard at all.

Posted: Sat Sep 27, 2014 12:04 am
by TonyW
DolwyddelanLightRail:104387 wrote:The double engines (bar DLG) never worked well on oil in the first place, from the stories I've been told on the Meld and Square it used to be ramp it up leaving port and hope for the best.
It is interesting to know that stories like this are still being told, for that is what they are: just stories.

I didn't do many turns on Merddin, but I fired the Square countless times in the 1990s and never had a problem making steam or maintaining a safe water level.

It was only later that things changed.