I was watching a video about Canadian steam engines and noticed on several engines below the cab windows there was a 53% or some other number painted on the cab.
I am curious as to what they are referring to. Any ideas?
Joe
I’m led to believe it is the tractive effort rating of the locomotive:
4070-Photo-Backups-261 by Edmund, on Flickr
i.e. this USRA Mikado would have a 55,000 lb. tractive rating.
Alco_USRA_0003 by Edmund, on Flickr
As shown above, tractive force is rated at 54,700 lb. and the GTW may have rounded it up to 55,000 using the % as a symbol for x 1000.
I could be mistaken. Others may step in with further information.
Cheers, Ed
Oh, c’mon, Ed. You know better than that!
Ans: it’s the day’s exchange rate for the CDN$ vs. the USD$. That’s why those ratings were changed at midnight every night. Part of hostler’s job was to carry stencil, two paints (Engine Black, White), and correct the exchange rate for next day’s revenue hauls across the borders.
Could be the income tax rate of the engineer?
Cheers, Ed
[(-D][(-D][(-D] Now that’s funny!
Ralph
There’s not much humour in the exchange rate for us Ca-knuckleheads, though.
Wayne
Thanks Ed, that sounds reasonable.
Joe
That wasn’t a Canadian-only thing; some US railroads (U.P. for one IIRC) did it too.
Stix, what UP classes did that? In my experience they put just about everything BUT the FA or adhesion percentage on the cab (including weight on drivers and cylinder proportions).
In any case 55% isn’t going to be a direct measure of adhesion, which would be in the range of 4 (or 25% weight on drivers) to mean something on the kind of engine pictured. About the lowest FA I know of in service is the N&W J, which I recall as being about 3.31; even that would be fantastically slippery if not handled with care and respect (and indicates that a large percentage of ihp was intended to be used fully only at high cyclic/road speed)
I’d be more inclined to speculate it’s a practical ‘derating’ of something calculated, like PLAN or other ihp, for practical train make-up purposes, perhaps varying by division.
It is an interesting question, though. I has nothing to do with cut-off limit, estimated shelf life remaining for the boiler (why not just the last date shopped),…?
I googled the question and came to this site:
CNR Steam Locomotive Roster - Notes (trainweb.org)
Apparently, for CNR at least, each 1k of TE was designated as a percentage. So, maybe in the case above, 55% = Total TE for the locomotive.
In the Kettle Valley Railway book, pages 30-31, in the locomotive roster there’s a column headed up “Cap.” “%” with numbers varying from a low of 27 for a 4-4-4 to a high of 210 for a 4-6-2.
None of the photos in any of the CPR related books I have show the % number on the cab.
Pre 1928 numbering shows "C.P.R " with the road number on the cab. After that freight locomotives show the road number on the cab while passenger locomotives in maroon/grey have the herald only on the cab, the road number moved to the walkway fascia.
CPR did not own a class of steam locomotive of a S-3-a series nor did they use the 4000 road numbers for steam as far as I can tell.
The internet says 4070 was assigned to this CN Mikado only in 1957 and no photos show the cryptic model number or %.
Wonder when these graphics were added and by whom?
I was just saying that I’ve seen several railroads that put a lot of “fine print” on the engine cab, often with a “%” in there representing…something. Maybe I’m thinking of one of the other “Pacifics” (Northern, Southern)?
What, exactly, are you trying to say?
6218_Chatham-cab by Edmund, on Flickr
The 4070 was the former 3734 and, as I mentioned in my first reply, was a Grand Trunk western locomotive.
Cheers, Ed
In other words, analogous to the current ‘axles of power’ rating for different units (as I recall, Conrail rated the SD80s as eight axles when introduced, either for the AC traction or enhanced dynamic braking…)? EDIT – I am advised that the ‘percent sign’ is just a placeholder for the ‘1,000 lb TE’ that selector mentioned, and it doesn’t mean a “percent” of some other number. We are getting definitive confirmation in a few days.
I am told we will have expert confirmation of details of the CP system on the Kettle Valley in a few days also, from a pretty definitive source.
I was beginning to think ‘percentage of weight on drivers’ but that 210% threw that idea out the window.
Stix – see what you can find for ‘them other railroads’. Perhaps one of them uses the percent sign a different way, or lists locomotive performance more directly as it would affect determining consist for a given train factor.
Which book?
Gerry Doeksen. Subtitled (Railways of Western Canada) 2nd Edition (Volume One). 1995.
First edition was 1981. The author would now be 85 years old so possibly no subsequent works.
As far as I know there is no Volume Two.
As far as the graphics on 4070 I noticed there were no such graphics on any of the photos available on the Internet. For me this begs the question: who added them and when. The why has been asked and it is suggested it originated in Canada. If so, it would be some time after the renumbering in 1957 (or whenever) and the graphics were not common practice up here judging by the complete absence of photos of same on any CPR locomotive, for example.
It is intriguing that such numbers exist. For what purpose they would be lettered on the cab is interesting.
You keep talking about CPR when it was CNR that did this as a regular practice.
And yeah as said by several above, the “%” marking is x1000lbs tractive effort, not “percentage” of anything.
The “S-3-g” is CN’s locomotive class.
I checked my Morning Sun books of CP and CN, which contain pictures taken mostly in the late 50s. The vast majority of CN engines had these markings on their cabs, below the number. CPR did not seem to have these markings, at least not on the cab.
Simon
Now the thing to do is review pictures of Grand Trunk Western steam on the Internet and in books and see if they carried these numbers … or if GTW engines acquired them if renumbered for a Canadian system.