Hey Kevin --here I am again
Steinways ---anyone notice there were NEVER any trailer cars ---anyone now why ? (heh, no---!)
Steinways, named after the tunnel name, named after the Piano manufacturer who invested big $$$ with "Augie" Belmont on the Rapid Transiting of the line--were special cars with smaller motors and much lower gearing.
They were built on the dawn of the Low-Volt system being used for the IRT, 1918, and were constructed with a sample group of Low-V "standard Motor performance" mainline IRT cars. "Mainline (or standard) Low-v cars had larger motors and were geared for speed and trailer use in trainsets...and could handle moderate grades known to IRT constructions then (excluding the Steinway tunnels originally built for "single streetcars")
OK, to further continue --
Mainline Low V Motor cars could Couple up to Steinway Motor Low-V's fully, - however, the gear ratio is so different between the two classes that -- well, run a model subway car with a 20:1 gear ratio (geared high and the standard for normal speed) with a model subway car with 29:1 gear ratio (Geared LOW & SLOW, for grades and a good load puller).
The wheel tractive effort and torque and speed is different --same with the Steinway Low-V & Mainlne Low'V --the bucking and banging and unequal acceleration and speed rangers when mixed together
would not provide a smooth transition from stop to speed.
The 1939 Worlds Fair car Steinways (ONLY 50 MADE - ALL MOTOR CARS ) were built 'under the floor" the same as their earlier, older companions, and geared the same.
When transferred to Mainline IRT in 1950 (replaced by R12-14-15 smees) All Steinways, being all Motors, ran in trainsets of their own ONLY -(mainly # 6 Pelham co-existing with separate trains of Hi-V trainsets on that line.) and occasionally a Low-V trailer car or two worked in as all the Low-V trailer car was --was an extension cord for low-v MUDC door and motor control and lighting circuits---between Steinway motor cars---having the same electrical circuit for Low-V Steinways as for Low-V Mainliners.
To repeat, the motor size was smaller and the gear ratio lower (like driving your automobile in 2nd gear at 60 mph instead of higer 3rd gear !!)
Thus, Steinways all were motor cars and had a RED line under their exterior car numbers to designate their "different" class.
So, on the 3rd ave El, a Low-v trailer made a 5 car train using 4 Steinway Motor cars. Those one trailer car(s) per 5 car train saved them extra scarce working Steinway motor cars for an extra train set or two with a few spare motors for breakdown replacements...rather than using up all the remaining and dwindling Steinways as 5 car motor trains. They were trying to stretch the motor car stock inventory until they could dump the line. Those were desperate financial times for the TA and DA CHITTY back in 1970.
Eventually they had to bring in Kevins's favorite cars - the "AArrr"-12-14 SMEES to the (his) line to bail it out til the end from early 1970 thru April 1973 closing of the EL.
So, now you know what Steinways are all about --never had trailer cars for the Flushing line. Smee cars with 4 motors per car and no R-type trailers, were very adequate -even loaded, for Steinway Grades outfitted and geared as they were fron the factory as new" for the "whole IRT system"
Of course, a Steinway Motor could have a low geared power truck swapped with a Mainline Low-V, and itself become a (and syncro-mesh with, gear wise) a mainline Low-V...but like the IND # false "R-10" # 1575, it would be an odd ball and could not again run with its Steinway former mates...and Vice-a-versa !!
I hope I have cleared things up!
Regards - "Unca" Joe