yes it was first time for M-8 to be powered by 25kv.
the 25 Hz transpormer has been discussed ad nausuem and is way to heavy plus if used to NYP they be powered by LIRR third rail, not catenary.
One pair could not pull train trough phase or power gap as power switchover and pantographs are not able to be controlled by engineer on individual pairs.
no the third rail shoes do not retract, they have fixed possistion. with a sping controlling tension on LIRR or MN third rail.
Any one know if this first time for any M-8 to operate under 25 Kv? Imagine MNRR will want to know results as well. That will be for M-8s running to Springfield when that line gets 25 Kv CAT. Is the voltage change location in New Haven on level track ? That would enable lead EMU to pull rest of train thru voltage change.
The Amtrak Hell Gate line was converted some time back from 25 Hz to 12.5 Kv 60 Hz from Gate CP ( near Sunnyside ) to New Rochelle for several reasons.
1. CAT needed rebuilding ( constant tension ? )
2. 60 Hz to 25 Hz transition moved away from New Rochelle preventing any chance of a stall fouling that intersection.
3. With the new ACS-64s coming on property the possibility of 4 ACS-64s and a couple of Acela trains all on that segment might have severly overtaxed the 25 Hz Sunnyside frequency converter substation.
4. In reference to #3 gave Sunnyside yard and NYP a more reliable and less demand 25 Hz system. As well Sunnyside could power North river tunnels and beyond in a pinch. However we are aware of the problems with the CAT feeders in the North tunnels. Have not heard of problems in East Rivier tunnels.
The transformer situation of M-8s on 25 Hz has not had any solution disclosed. 25 Hz transformer would be much larger and heavier but completely useable on 60 Hz. Probably would have a center tap transformer for 25 Kv. Some where it was posted that the power drain on the present 60 Hz transformer could be limited when on 25 Hz. A problem that might occurr is if train is stopped at bottom of East river tunnel and has to climb out. That might be a big problem if Amtrak's 12 Kv 25 Hz line voltage decreases to the lower limit of 10.2 Kv (?). It does happen.
Would imagine that before a M-8 train left New Haven that the under running 3rd rail shoe is verified retracted.
Question arises why not convert Sunnyside = Newark Penn to 60 Hz. Money and time. The old PRR electrical equipment has many components not 60 Hz capable. As well Amtrak in its early years did not buy dual frequency equipment. Now all new equipment is dual frequency capable but have no idea when that started. As well there may be items in the present North river tunnels that cannot be replaced until the major closings for rebuilding after Gateway bores are in service. Would look to 2030 - 2035 for even any attempt to change frequency. 12.5 Kv will be final voltage as higher not possible due to clearances in the present NYP and tunnel bores.
MidlandMike Were those M-8's modified to handle 25 kV, or do they come that way?
Were those M-8's modified to handle 25 kV, or do they come that way?
The M-8's were build to run both on 12.5 Kv 60 hz or 25 Kv 60hz, the yard switcher was not being pulled by M-8 but was shoving the M-8 past the voltage change near Mill River, once under 25Kv the pantograph was raised and some testing performed. running M-8's in service is a long way off, as ACSES testing etc still has to be done plus doing voltage change on the fly with multiple cars. the single pair in video is assigned to Amtrak for while for testing.
Note that this does not mean that they can also operate on 25 Hz from Sunnyside into Penn Station. Larger transformers would be required. But eventually that will aslo be 60Hz.
Shore Line East is eventually to be mu electric, replacing diesel operation.
Married pair of M-8s being tested on Amtrak east of New Haven. Note yard switcher being pulled by M-8s. That is probably due to verifying that the M-8s have no problem transitioning from 12.5Kv to 25 Kv in case they should fail ?.
https://www.youtube.com/watch?v=oJCdin6_nTE
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