BandA wrote:Soft coal...does hard coal burn at a higher temperature? Which is cleaner or less corrosive?
I thought that the 7470 was a lower-power locomotive. If it was designed to run at <40 MPH the gearing would be different than the road locomotive. Gearing on a steam locomotive was basically the size of the drive wheel, right? A yard switcher would also have a smaller tender I imagine.
Refresh my memory - the 501 would be typical of what the MEC was running on the Mountain Division in the 1930s??? I imagine asbestos steam locomotive brake pads were a lot cheaper and better performing back in the day than non-asbestos custom pads are today, and so would have been labor, so I assume changing brake pads frequently wasn't a big deal.
Hard coal is known to have a very high BTU rating, hard coal does burn cleaner but soft coal has the advantage of instant volatility when a quick hotter fire is needed in short order, however soft coal usually has a higher sulfur content & comprised of Bituminous ( tar like components ) it produces more smoke until it's volatile chemicals are burned off.
#7470 does not have gears, the size of the drivers & no front truck allows all it's weight to be utilized for traction effort at slow speeds like switching in a rail yard. The general rule of thumb is the larger the drive wheel diameter the more capable of higher speeds but can come at the cost of lower tonnage pulling power. Like the NYC RR #999 that set a world speed record using 86.5" diameter driving wheels, boiler pressure & locomotive weight also played a role in her ability to make 112 1/2 MPH.
MEC #501 was put into service after arrival in 1910, it's services were utilized all over The MEC system including The Notch, it was the last official live steam locomotive to make the round trip from Rigby to St. Johnsbury and back in 1950 as steam was brought to a close on The Mtn Div that year.
When a railroad purchases brake shoes and / or pads they buy them in bulk, it's cheaper by the pallet load & many different type of designs and material make up are available allowing the railroad to customize, therefore getting the most bang for their buck.
Hope I explained it in a understandable fashion.
I have a MEC RR Employees Magazine that I'm going to locate, copy & post on this Forum. It will do a great job to allow those interested railfans to broaden their horizons regarding what The MEC Operations & Mechanical Personnel thought about the Class " W " 2-8-0's like #501. Hope to have it up within 24 hours.
Love me or hate me.....I've kept the " Flame of Hope " lit & burning for MEC #501 since 1995. J. Smythe... Former Master Mechanic MEC #501 Project 1995-2000.