I Think the current maximum speed a US FRA passenger train can run across a switch is 65mph. Has the maximum speed gone higher? Does anyone know the maximum speed across switches in foreign railways go for? i:e France TGV
I know of the existence of switches rated for 125mph in Europe, and I am fairly certain that there are switches rated for a speed higher than 65mph on Amtrak’s NEC.
Diverging thru it, you mean-- right?
Like he said, there are maybe a few dozen 80-mph x-overs and turnouts between Boston and Washington. They say LIRR has ten 80-mph x-overs at Queens now. A few years ago one or two equilateral turnouts north of San Diego were supposed to be good for 90 mph on Amfleet trains.
I do not know their top speed but some French TGV routes have turnouts that have three switch machines. 2 to move points and rails and one for movable frog.
I didn’t see a specific speed limit - such as one related to turnout ‘size’ / frog angle, or even the switch geometry, etc. - in the FRA’s Track Safety Standards Compliance Manual, Chapter 6 - Track Safety Standards Classes 6 Through 9, at: http://www.fra.dot.gov/downloads/safety/track_compliance_manual/TCM%206.PDF [101 pages, approx. 366 KB in size], such as §213.353 Turnouts, track crossings and lift rail assemblies or other transition devices on moveable bridges on pages 6.82 - 6.87 [pages 82 through 87 of 101 of the ‘PDF’ format version].
Instead, from §213.307 Class of track; operating speed limits, under Application in the middle of page 6.14 [page 14 of 101 of the ‘PDF’ format version]:
‘‘As in the lower classes, the high speed standards classify track solely on the basis of authorized speeds of freight and passenger trains, irrespective of traffic density, axle loads, trailing tonnage, curvature, grades, or rail weight. Tolerances are specified in the TSS for each class of track.’’
That said, as a practical* matter,
That’s quite a switch. What about those reverse curves beyond the switch? Is this a telephoto picture with foreshortening of the whole arrangement?
Amtrak has a handful of #32.8 turnouts good for 80MPH (Zero Crosslevel, 3 1/2" unbalance or slightly faster with FRA Waiver and 4" unbalance), complete with swingnose frogs.
The issue isn’t the track, the issue is rather the railcar design as PDN pointed out above. Freight railroads have plenty of #24 turnouts (60 MPH) in the high speed mains…The Santa Fe southern Transcon is full of them. The issue becomes justifying maintenance costs versus frequency of use. The european railroads have subsidies that Amthrax would die for. They do pretty well in the NEC, considering how much they have to justify their costs.
They’re vertical curves – sags-- not horizontal curves. And yes, it’s a long telephoto.
50 mph, you mean? Do they still all have 39-ft switchpoints?
I believe that BNSF’s high-speed turnouts have 60-ft. long switchpoints, with shallower angles, too - at least that’s what the FRA tested and was reported on at the AREMA presentations. The Swiss turnout in the link that I posted above has points that are 65 meters = 200 ft. long per the caption. That also provides a correlation for the extreme distance compression in that photo - it has to be several hundred feet from the ‘Last Long Timber’ to the start of the return/ reverse curve, which itself is likely a couple hundred feet long. So yes, it all looks much sharper than it really is. - Paul North.
The data with the photo says it was shot with a 300 mm lens - a pretty long lens…
Good catch Timz…I fat fingered that thing I guess. (Stunned by a decimal size turnout 32.8[%-)])
#24 = 50 MPH (equivilent curve radius = 5424.25’) 1d 03’ 23"Cv
#20 = 40 MPH
#14 = 30 MPH
#10 = 15 MPH
#8 & #6 1/2 = 10 MPH
BNSF still using the ATSF style 39’ Sampson Undercut Points with hook plates on their #7, #9,#11, #15, #20 and #24s, predominantly in the faster speed turnouts (#15 and above …and keeping the bolted 16’-6" stuff in the smaller stuff, almost never see 11’-0" points anymore unless it’s in a really tight/cramped piece of track geometry.)