As a steam to diesel transition modeler. Looking at thousands of photos through the decades I have noticed that the early 1900s to around the 1970s that mainline track used 4 bolt joint bars. You rarely see any 6 bolt joint bars until the use of continuous welded rail came into favor. Is it an FRA regulation on the length of joint bars or standard practice? Are 4 bolt joint bars even used today?
Just some silly things that ricochet around in my head sometimes.
Pete.
I seem to recall seeing quite a few six-bolt joint bars in use at least by the 1940s as loadings and the corresponding rail weights increased. There may be a cutoff as far as rail weight goes as it seems most of the 100 lb. and over weights use a six bolt bar.
NYC Rail Data 1942 Joint Bar by Edmund, on Flickr
I think the maximum rail weight in use on the NYC at the time was a 127 lb. Dudley section. There was a design of a joint bar that had more of a clamping arrangement that fully surrounded the rail base. I'll have to do some digging to find that.
Rail tended to sag at the ends and a longer joint bar provided better support but also required the additional bolts. Some rail was specifically hardened toward the ends.
How about a 'compromise' joint bar?
track bars 2 by Edmund, on Flickr
Interesting.
If I find more I'll add it.
Regards, Ed
Ed.
Thank you. I know that the transition bars were longer six bolt affairs. Even some insulated joints were six bolt too. But a majority of rail of different weight used the 4 bolt bars. Even on the Broadway of horseshoe curve you can see 4 bolt bars with decapods dragging hoppers behind. I was just wondering if there was some time period or the reason for a change.
Don't knock yourself out digging around. Like I said. It's just something that would run through my head and I had to ask.
Railroads relied on various trade organizations and engineering consortiums. A.R.E.A., A.S.T.M and A.R.A. are a few. They came up with metalurgy and design characteristics. The railroads, of course, would use their own engineers to 'personalize' these recommendations for their own conditions.
I forget the exact statistic but I read something about the rail on the 'Curve' needing to be replaced something like every eighteen months or thereabouts.
Here's a shot from April of 1948 near the Curve On the Pennsy main:
12 Two K4s and a T1 near Gallitzin April 1948 by Edmund, on Flickr
Six-bolt splices have arrived here. The Pennsy was known for its extensive use of heavy rail, some of it at 155 Lb. per yard.
This six-bolt joint bar dates to 1908:
PRR Six Hole Splice, 100 lb. 1908 by Edmund, on Flickr
—and this is from 1946 showing a splice for the 155 lb. rail:
PRR Six Hole Splice Bar 155 LB rail by Edmund, on Flickr
Cheers, Ed
Yes, 4 bolt bars are still in use. Mostly in yards and secondary tracks. You can see 6 hole bars with only 4 bolts used on some main tracks. They won't be higher speed main lines, but slower secondary and branch lines.
Jeff
The 4 track New Haven main line used 6-bolt bars. Seems they were there from when I was young (1950's) until it was finally all replaced with welded rail (1980's).
I'm guessing that the 6-bolt bars were used from the last time the stick rail was upgraded. 1930's, perhaps?
I have a photo or two of compromise joint bars that are 3 bolts for the heavier rail, 2 bolt for the lighter. I no longer recall what the relative rail weights are, but I agree that there are still plenty of 4 bolt joint bars out there, on lighter rail sidings and such.
Dave Nelson