MM Class 121 No. 121 Marker Lights.

[Fowler4f]

I’m running in No.121 on DC and noticed the marker lights at cab end show 3 white with 1 red at bonnet end. Is that correct ? Please note I have yet to fit DCC sound decoder. Thanks

 

[DiveController]

Yes, it's correct for the model. Interesting because I had looked at many photos of them before and you don't always notice the lights.

The assumption is that with 4 marker lights, they'd have 2 red and 2 white in each direction They had a single red as did the 141 and 071 when delivered (although they came with 2+1 light clusters, not 2+2).

Unlike the 141, 181s and big Gms that followed the 121s were delivered with 2+2 clusters. Here's one being unboxed 

 

You can clearly see that three of the markers are white in 122s

 

I think a lot of switching took place as needed to keep the close operative 130 with 3marker light 

....and 130 with 1+3 prior to that. It may be possible that spare from 141/181 were available more readily as time elapsed that for the 121 as the 2+1 cluster seem to be more common later in several locos including 123, 124, 128, 130 132 and probably more 

 

Al that said, what was lit is a bit of a guess and needs to come definitively from someone closer to the railways the me, I se nor more than 2 white lights lit here

 

 

Edited September 28, 2021 by DiveController

[DiveController]

I was pretty confident that a grocer or ex-railwayman would oblige with a definitive answer on the 121 marker light when 4 are present. Although delivered with  two paired clusters, many of the 21s ultimately ended up with only three, one red and a pair of whites appropriate to the direction. The 2+1 arrangement may have occurred to keep the locos serviceable but if this was sufficient did they ever run with a three wholes (a pair of adjacent whites on the drivers side). It seems like the marker lights were used very little especially during daylight running and it is difficult to be certain how many are in fact light in phots as the locos are often not shot head on (at least when in motion, lol) and ti is difficult to appreciate more than 2 lit any any one time. When the shot is backlit, it is easier to appreciate what bulbs were actually lit but I'm going to say that 2+1 was the functional arrangement and the arrangement with three lit in the MM model is probably not prototypical (if anyone knows different, please feel free to contribute). there doesn't; seem to have been a second red glass, one red light only on the rear left.