west point wrote: ↑Fri Jul 08, 2022 1:54 amThat is an importnt quetion. There are overhead rail sysems with proper insulation above rail that can allow OCS ( overhead contact system ) within a few inches of the underside of bridge. But with 25 kV OCS you still need at least 23'6" - 23 feet height above top of rail . That is if the track does not have any dips or crowns within 100 feet of the limits of bridge profile that might cause top of car to be higher.
Then if the clearances needed cannot be met either =
1. Raise bridge by far best option . Raising bridges has become very easy around here.
2. Lower track not always possible.
3. have OCS a dead section going under bridge. MNRR does thhat on at least one of their movable bridges.
The track looks pretty smooth and level in those areas, I just don't know if they planned for 25kV/60 wire overhead when building the high clearance track. Some of those areas appear to be tight on clearance, as the high clearance track is noticeably lower than the two Amtrak tracks, which presumably only clear the T at 15'11" or maybe F.
The wire under the garage at TF Green couldn't be dead, as that's a T stop.
MBTA3247 wrote: ↑Fri Jul 08, 2022 6:08 amThat's been electrified for over 20 years, so yes.
It is not electrified from Warwick to Providence, where only the 3rd track has clearance for autoracks, and no wire. It is used by the T during the day for the Wickford Junction trains to service TF Green and P&W at night for WODA and DAWO, separate from the two electrified tracks used by Amtrak. From Warwick south to Davisville, the autorack traffic runs on the 2-track NEC mixed with the T and Amtrak, and the wire is high enough up to clear the autoracks. I'd presume that south of Davisville, it drops to Plate F or the 15'11" T clearance, and WODA has to drop the autoracks in Davisville for the occasional run down to Arnold Lumber in Kingston.
I don't know if they planned the height necessary when building it to accommodate 25kV/60 wire above autoracks. I would hope so, as the electrical system is designed to be upgraded for use by the T, but I don't know for sure.