Strange Looking Locomotive at South Station

[F-line to Dudley via Park]

it isn't used for commuter rail maintenance at all

...

There's no interconnections between rapid transit lines, or any currently active interconnections between the rapid transit lines and adjacent commuter rail lines.

Which raises the question as to why it is at South Station at all.

Well, it wouldn't be immediately at South Station. But it could be anywhere on the Cabot property, which puts it potentially as close as 1200 ft. from the tip of the South Station platforms. And if it's on the shop tracks instead of over by the work equipment line on Foundry St. you'd be able to see if from every passing Old Colony and Fairmount train.


This isn't commuter rail's to play with; Keolis isn't qualified on it, in addition to the rapid transit wheel profile making using it a slow and ginger proposition on standard RR tracks to avoid derailment. It's just used for jobs where more power is needed to haul a load (ballast, something on a flatbed or dump car, etc.) than a regular work motor coupled to a trailer can reliably haul. It lives on Red when it's not out on assignment elsewhere in part because the Mattapan PCC's are too weak to haul any work equipment, so it comes down from Cabot and uses the Codman Yard track connection when there's some sort of heavy trackbed maint going on with the High Speed Line that plain hi-rail trucks can't handle.

But it's not all that inherently powerful...just more powerful than the standard rapid transit work motors (and because the 01400's are now kaput in the Cabot dead line and immovable except in dead tow, the work motors on any given night are pretty much just a rotating cast from the revenue fleet coupled to a trailer). Commuter rail has 4 active work locos., the "weakest" of which is the 1750 HP GP9 #904. This 700 HP midget is too much of a weakling to be of much use for a commuter rail work job.

[The EGE]

Yeah, that's the building just South of the Broadway bridge in Cabot Yard.

[BandA]

What is the difference in the rail profile between the subway / trolley lines and CR? And why?

[F-line to Dudley via Park]

What is the difference in the rail profile between the subway / trolley lines and CR? And why?

Trolley vs. railroad flanges, mostly. Because by mode light rail runs on a whole lot more street-running trackage than the relatively tiny number of small and speed-restricted route miles RR's run street-running. Light rail (trams) and heavy rail (metros) converged on the same wheel profile because lots of systems share work equipment between LRT and HRT lines, and it sort of froze along those lines.

This little graphic off Wikipedia shows the difference:


Railroad (left) and trolley (right).

It's a minute difference in how they grind the wheels. You can hold a trolley to a railroad track and vice versa if the railbed supports the weight and the speed's slow enough. It's done on Newark Light Rail where the recent Broad St. extension has a very tiny overlap of a several blocks where occasional Norfolk Southern freights cut down the same LRT-profile tracks the trolleys use during the day. But it's mint-condition track and NS crawls on it so slowly they don't risk anything, so it's safer to run on perfect track of different wheel profile than it is running on the countless dodgy sidings and industrial tracks across the country. But it wouldn't, say, be an appropriate application for full-on blending full-speed trolleys by day and freights by night on the same tracks. Even the FRA-exempt NJT's RiverLine has got its cars ground to RR profile. So unfortunately I wouldn't hold out much hope of the RiverLINE, Newark, and Hudson-Bergen Light Rail all becoming some super-unified superinterurban thingy. RiverLINE cars might be a little bit of an adventure trying to take a stiff curve at track speed on its sister LRT trackage. The derailment odds tick up enough that revenue service intermixing is a little too much to ask for.


Less a feasibility issue (it's been done) than simply a not-ready-for-prime-time / not-ever-ready-for-primetime. Basic common sense says "yeah, don't push your luck."

[Ridgefielder]

What is the difference in the rail profile between the subway / trolley lines and CR? And why?

Trolley vs. railroad flanges, mostly. Because by mode light rail runs on a whole lot more street-running trackage than the relatively tiny number of small and speed-restricted route miles RR's run street-running. Light rail (trams) and heavy rail (metros) converged on the same wheel profile because lots of systems share work equipment between LRT and HRT lines, and it sort of froze along those lines.

This little graphic off Wikipedia shows the difference:


Railroad (left) and trolley (right).

It's a minute difference in how they grind the wheels. You can hold a trolley to a railroad track and vice versa if the railbed supports the weight and the speed's slow enough. It's done on Newark Light Rail where the recent Broad St. extension has a very tiny overlap of a several blocks where occasional Norfolk Southern freights cut down the same LRT-profile tracks the trolleys use during the day. But it's mint-condition track and NS crawls on it so slowly they don't risk anything, so it's safer to run on perfect track of different wheel profile than it is running on the countless dodgy sidings and industrial tracks across the country. But it wouldn't, say, be an appropriate application for full-on blending full-speed trolleys by day and freights by night on the same tracks. Even the FRA-exempt NJT's RiverLine has got its cars ground to RR profile. So unfortunately I wouldn't hold out much hope of the RiverLINE, Newark, and Hudson-Bergen Light Rail all becoming some super-unified superinterurban thingy. RiverLINE cars might be a little bit of an adventure trying to take a stiff curve at track speed on its sister LRT trackage. The derailment odds tick up enough that revenue service intermixing is a little too much to ask for.


Less a feasibility issue (it's been done) than simply a not-ready-for-prime-time / not-ever-ready-for-primetime. Basic common sense says "yeah, don't push your luck."

Back in the day-- way back-- when the New Haven owned the Connecticut Company trolley system, there were several routes that saw joint steam road and trolley operations: where the NYNH&H strung wire over their trackage between towns. Hartford-Rockville CT springs to mind, for one, as does Norwich-Jewett City. Were wheels ground differently in those days, or is that just an artifact of the more shall we say casual attitude our great-grandfathers had toward safety in general?

[CannaScrews]

Good question!

There were many instances of streetcar routes carrying freight. Another comes to mind in CT is in the Waterville section of Waterbury, there was an interlocking roughly where the soon-to-be-former Commons Road crossed the NYNH&H tracks on the Winsted Line where freight was pulled by electric traction south on Thomaston Ave thence north up the Homer St hill (Huntingdon Ave/Chase Ave), onto North Main St to serve the industries up there.

I'm not a street transit (trolley-jollies) person, but maybe some lurkers have a good explanation they can share.

Offhand, I'd say the reason why the wheel plates are thinner on streetcars is that they were lighter & didn't need the structural support of a thicker plate. However, you had less of a variation allowed in the track gauge. RR gauge can be as much as 2" wider than the standard 56 1/2" track.

[CVRA7]

Regarding wheel profile "steam railroad vs trolley" - I seem to remember reading that the Rockville - 'Hartford' cars only went to East Hartford (Main St.) and passengers had to transfer to city cars at that point to continue to Hartford, and this was due to "flange depth."
Another area where trolleys and steam trains mixed frequently was in Middletown CT. An old-time signal station operator told me that the quarter mile north of the diamond on the Valley Line was the busiest stretch of siongle track on the New Haven Railroad due primarily to electric operations converging there from Cromwell, Berlin and Meriden in the early 1920s.

[Ridgefielder]

Good question!

There were many instances of streetcar routes carrying freight. Another comes to mind in CT is in the Waterville section of Waterbury, there was an interlocking roughly where the soon-to-be-former Commons Road crossed the NYNH&H tracks on the Winsted Line where freight was pulled by electric traction south on Thomaston Ave thence north up the Homer St hill (Huntingdon Ave/Chase Ave), onto North Main St to serve the industries up there.

Then there's the former E. Hartford - Glastonbury Connecticut Company line, that actually survived the end of trolley service in Hartford by something like 25 years as a freight spur servicing Pratt & Whitney. Was that relaid with heavier rail when the ConnCo bustituted the Hartford division in 1941?