Guessing the last thread got political and that's the reason it was deleted. So keep it clean people.
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OK so this got me to wondering how are the trains running if it is "out of gauge"...seems it is out of spec.
excerpt from article in trains.com
"The Green Line, like other MBTA transit lines, is standard gauge, or 4 feet, 8½ inches. WFXT-TV reports the construction contract required a track gauge within a sixteenth of an inch of that standard in either direction, while the threshold for slow orders is anything narrower than 4 feet, 8 1/8 inches. Currently, the entire extension is above the slow-order threshold, but about a half-mile on the Union Square branch and 2.7 miles on the Medford branch is narrower than the 4 feet, 8 7/16 inches permissible under the contract"
They are running at very slow speeds along the sections out of spec ... as low as 3 mph in some places. Luckily, I use the Blue Line or the commuter rail when I have to get into Boston on business.
It's inconceivable to me, with all the latest instrumentation and technological advances, how tie plates can be installed so that the rail gauge is out of spec.
My understanding is that each offending tie plate has to be removed, holes filled and leveled in the existing ties, new holes made for the tie plates with the rails now in spec, and the tie plates then installed - lot of work.
@Richie C. posted:They are running at very slow speeds along the sections out of spec ... as low as 3 mph in some places. Luckily, I use the Blue Line or the commuter rail when I have to get into Boston on business.
It's inconceivable to me, with all the latest instrumentation and technological advances, how tie plates can be installed so that the rail gauge is out of spec.
My understanding is that each offending tie plate has to be removed, holes filled and leveled in the existing ties, new holes made for the tie plates with the rails now in spec, and the tie plates then installed - lot of work.
Interesting. Here are a few thoughts:
1) All tie-plates have an "inside" and "outside" position, in order to tip the rail at a prescribed angle and thus "match" the wheel tread profile of either 1 in 20 taper (freight) or 1 in 40 taper (passenger). Thus, were the tie-plates incorrectly installed?
2) Which rail would be "moved" in order to correct the problem? Are there turnouts involved?
3) What with all the current running slow through the incorrect track gauge, what is happening to all the wheel flanges?
on a lot of big jobs where massive amounts of ties are being replaced ties sometimes come with the tie plates attached to the new ties , maybe where the problem came in. as far as tolerance you have an inch and a half of play in the gauge before action needs to be taken for wide gauge not sure where the line is drawn for the gauge being narrow. worked on the railroad most of my adult life and never saw a tie plate that had to be installed one way or the other.
@Hot Water posted:Interesting. Here are a few thoughts:
1) All tie-plates have an "inside" and "outside" position, in order to tip the rail at a prescribed angle and thus "match" the wheel tread profile of either 1 in 20 taper (freight) or 1 in 40 taper (passenger). Thus, were the tie-plates incorrectly installed?
2) Which rail would be "moved" in order to correct the problem? Are there turnouts involved?
3) What with all the current running slow through the incorrect track gauge, what is happening to all the wheel flanges?
All good points - my understanding is that the tracks are out of spec by approximately 1/8" too wide. My guess is that the wheel flanges are probably wearing prematurely and will likely have to be replaced earlier than their expected useful life.
As Rick suggested, the problem stems from the fact that the plates were pre-installed on the ties and, apparently, no one bothered to check either before or after installation. Not sure how they will determine which rail to move. Perhaps they can go back to where the rails were last in spec and then try to determine if one rail deviated more than the other.
@Richie C. posted:All good points - my understanding is that the tracks are out of spec by approximately 1/8" too wide. My guess is that the wheel flanges are probably wearing prematurely and will likely have to be replaced earlier than their expected useful life.
The wheel flanges can not be "replaced". The wheel sets can be machined in order to bring the wheel tread profile back into specifications. Otherwise, the wheels will have to be replaced.
As Rick suggested, the problem stems from the fact that the plates were pre-installed on the ties and, apparently, no one bothered to check either before or after installation. Not sure how they will determine which rail to move. Perhaps they can go back to where the rails were last in spec and then try to determine if one rail deviated more than the other.
I posted something sarcastic on the previous thread and may have caused it to disappear. I humbly apologize and I will see to it that any future posts from me are free of anything that could spoil enjoyment of these discussions.
