LIRR Questions

Howdy, all...

I'm back on LI and got to ride LIRR for 2 round trips from LI to Penn (first time in a while), and since I've been lurking here for quite some time, I realize that some questions that have been bothering me for years could probably be answered quite easily by the experts around here!

1. Simple and perhaps obvious, but why do the lights in M-1/M-3s go out periodically? I'm assuming this is from gapping between third rails, but does that mean that the entire car's power goes out? Thus, I assume, the cars in the consist that have NOT gapped carry the load and pull the dead car through the gap.

2. I've noticed a persistent "clicking" sound coming from the undercarriage of several M-1s/M-3s over the years. It's infrequent, usually only 1 car per train. Any ideas what this is?

3. There are several sets of switches just west of Bellerose between the 4 main line tracks (what is this interlocking called?). Why so many? Some look like they're lower-speed than others, but some look identical. Are all of them used?

4. Looks like they're replacing the concrete ties on one of the inside tracks (2 or 3, I guess) just east of Woodside. Was that planned, or are the concrete ties failing sooner than expected?

5. I watched a DM30 and 4 double-deckers scream through Mineola at high speed westbound (missed the glory days when I could watch 2 GP38-2s with 11 or 12 old coaches...sounded and looked so much cooler!). What's MAS through Mineola when not stopping? I couldn't make a guess at how fast this train was going...judging by the blast of air, pretty darned fast!

Okay, I think that's it. Sorry for pestering, and hopefully the answers to these aren't sitting somewhere else on this board and I've missed them.

Thanks!

Drew

Drew,

You have it correct in question #1.
The M-1 loses all it's fluorescent lighting in a 3rd rail gap.
The M-3 loses all but a few (if the emergency lighting circuit breaker is on, that is) as the emergency lights are powered by inverter ballasts, powered by the battery voltage. Those few emergency light fixtures should stay on. The rest go out.
The M-7 does not lose any fluorescent lighting in a gap because all ballasts are inverter ballasts. As long as you've got sufficient battery voltage or battery trainline voltage (if the battery set in that pair happens to be weak or dead), the fluorescent lights will stay on in an M-7 while in a gap.

And, yes, in answer to the second part of question #1, the car battery or battery trainline will also keep the low voltage circuits powered while in a gap. (Well, theoretically, if not always in reality. We do get M1/M3 trains lose power if head pair goes into a gap with dead battery. )

Tom

Question#3- The Interlocking is called "Queens" and is controlled by Queens tower.

Question#4-Mas through Mineola is 80 MPH for all Passenger equipment

Question number 2-the clicking is caused by the controller switching various sized ballast resistors in series with the motors as the train accelerates. The purpose is twofold-to protect the motors from burnout at low speeds, and to limit the acceleration for comfort reasons.

There is a more detailed description here. This thread also has some more info on the M1/M3 motor control circuit.

Tom-Good explanation on the lights on the M1/3 cars. I wondered why the lights could not stay on on third rail gaps. I noticed that MNCR's M2/4/6 lights stay on on the gaps coming into Grand Central. Thinking about power draw and third rail gaps,to me the classic example is the Stewart Avenue crossing in Bethpage-when a EB train leaves the last west shoe on a pair will noticably arc on the third rail end on the station side because of the power draw. MACTRAXX

Thanks, MAC.
In the LIRR M1/M3/M7, an M/A (Motor-Alternator set) or an APS (Auxiliary Power Supply) converter/inverter loses it's 750VDC input when in a gap. No input = no output, output from those devices being 220VAC 3 phase @ 60 hertz.
That lack of 220 VAC output shuts down not only your fluorescent lights, but also your evaporator fan motors, air conditioning compressor motor and condenser fan motor, and the air compressor, all of those being 3 phase 220VAC motors.
The only lights that can be on are those that are powered by the battery circuit. These would of course include the crappy incandescent emergency lights that are in the M-1, or a fluorescent fixture that is powered by a separate battery voltage powered inverter or individual battery powered inverter ballast.
In our M-7s, they elected to use inverter ballasts, some of which light one fixture, and some of which light 2 fixtures.

Tom

BTW There's one or two M-1 cars running around that have an M-3 style arrangement of inverter ballast emergency lighting as a test item. Of course this idea, an excellent one at that, was never implemented as a modification. The point is just about moot now.