I notice in old photos from the 1920’s that much mainline rail was very light weight: 85 and 90 pound.
What is interesting to me about this is that they were running heavy-weight coaches on that rail at fast, main-line speeds. That kind of high speed operation on light-weight rail is something I just don’t see today. Can anyone here comment on how they were able to get away with running so fast on such small rail? Was it because the roadbed supporting the rail was in prime condition? Was it because the rail was new, so less vulnerable to failure? Could they run Amtrak today at 79 mph on a track with 90 pound rail? (Yikes!)
I’m going to throw out a couple of educated guesses here (as much to show what an education can do to ruin you as much as anything else…LOL):
- I would think that Superliners weigh more than most passenger equipment of the heavyweight era, except for, perhaps, some of the heavier Pullman cars. Many of those had 6 wheel trucks, which would reduce the axle loads. I’m not an Equipment Register kind of guy but I’m sure that someone more familiar with such things could give us some comparative weights.
- It would be possible to run higher speeds on light track as in the past but it would require returning to the armies of trackmen that were forever tightening fishplates and shoring up low joints.
- The big detriment to track structure isn’t passenger train speeds so much as freight train weights-and the loadings per car, axle and wheel (as well as speeds) have gone up far greater than in passenger service. That what did (and will continue to) pound the living daylights out of the track. I would think passenger trains would need closer tolerances in alignment but with modern freight car capacities, you’d need as heavy and solid a structure as you could get.
Which pics are you looking at, where you can distinguish 90-lb rail from 100-lb?
(1) locomotives and wheel loadings were much lighter
(2) trains were shorter and lighter, less impact damage
(3) you had 12 man section gangs every 10 miles
(4) today there are unit grain trains running 40 mph on 90 and 100 Lb jointed rail from that era, it took extreme tonnage and time to generate rail-end batter and joint memory (even with Webber joints)…
(5) 110# and 112/113/115# rail was new big rail for the times (110# rail would later be cause for some heartache beause of railhead instability/ wobling)…AREA standards had replaced ASCE standards in large part because of real world experience in the industry in rail design…
The Soo Line had laid new 90lb on their main line between Glenwood,MN and Wimbledon,ND up until 1956. Just west of the Main St crossing at Wimbledon the 100lb rail started with 1957 dates. In the late 1970s the Soo still had sections of 85lb main track rail in ND and MN with 40 mph speed limits. As was said above the ballast and tie conditions had to be great to support this lighter rail and on the old Soo, they were. In the late '70s their trains were long, but mixed loaded covered hoppers, box cars, lumber, etc. They were not all 131 ton loads.
As a side note the Soo Line SD-40 and SD40-2s were lighter than most, averaged 367,000lbs rather than most other roads 390,000lb+. Only the 6615-6617 were at 390,000lbs.
Interesting.
I know of a stretch of former main line that had 90-pound, bolted rail that supported 50 mph passenger trains into the 1960’s. Not something I see in today’s rail landscape.
(Stray thought from rrboomer’s comments… I wonder if the SOO had mostly drag freights, time freights, or both?)
- Tiskilwa
In Argentina, the Buenos Aires Pacific Railway is STILL running with the 100 Lb/Yd Rail originally laid when the railway was built in 1905…
They have much lighter axle loadings than the USA, and most of their locomotives are “export” designs even though they use 5’6" gauge.
M636C
Standard practice on the Soo was to operate their trains at maximum tonnage on the west end in the '70s. An important secondary consideration was siding length (and often the length of every track at the same station as the siding), plus the length of trains to be met. Trains that were at full tonnage could usually make close to 40 mph on level track and minimum continuous speed for the units on the subdivision ruling grade.
For example in 1978 train #92/170 between Enderlin and Glenwood would usually get instructions to fill at Hankinson to 140 cars or 12,500 tons. That meant you would go up most of the hills between Nashua, MN and Glenwood at aprox 13-14 mph and would be able to fill the siding at Nashua and double to the house track if necessary. Otherwise there would be no meets unless the westward train could fit somewhere east of Nashua. In ‘78 you usually max out on cars rather than tonnage due to all the 40’ box cars still in service
The Soo’s maximum speed west of Mpls was 40 mph.
A map of the SOO Line’s west end to go along with rrboomer’s excellent postings:
(from a 1974 Official Guide)
- Tiskilwa
A map that brings back a few memories! In the 20’s or so, my grandfather spent a few years as a brakeman for the Soo Line (I still have his rule book). I remember him saying one run he was on was to Enderlin-it was a 15 hour, 59 minute run so they wouldn’t run afoul of the 16 hours of service law. I don’t know where that run would have been based out of-the Twin Cities seems too far for what was probably a peddler freight stopping everywhere (I assume that his short tenure prevented bidding on any but the lowest jobs on the board).
The crew terminal east of Enderlin is/was Glenwood, MN (137 miles) and west was/is Harvey, ND 139 miles. This was for freight crews.
Back then the frt train speed limit was 25 mph. So with way frt work, coal/water stops, fire cleaning, clearing for superior trains of both directions, etc they proably had to run their donkeys off to tie up 15’59". That allowed them to go back to work in 8 hrs instead of 10 if they worked 16 hrs.