I think it may prove both helpful and of interest to clarify the formations of the LNER streamlines here.
The first streamliner was the Silver Jubilee, introduced from September 1935 on a four hour schedule from King's Cross to Newcastle with one stop at Darlington. The outward left Newcastle at 10.00 am and returned at 5.30pm. One set of stock was used for outward and return.
The original formation was 7-coaches consisting of two articulated twins flanking a Restaurant Triplet Set:
BFK-SFO
FO-RK-TO
TK-BTK
The first class twin included a semi-open first next to the first class dining car, vehicles of this type were well used on the West Riding to augment restaurant seating and First class accommodation as necessary. On the Silver Jubilee however this was not this case.
The train suffered from overbooking despite the supplementary fare and so two measures were taken to improve matters. Within the first six months the balance of reserveable and dining seats was altered with 32 reserveable seats added by making half the dining car bookable seating in addition to altering some of open seating from 1+1 to 2+1.
This aided matters but the issue of capacity remained and so in 1938 a further 35 Third Class seats were added by building a 45ft 11in Corridor Third to fit inside the trailing Third class twin making it into a Triplet of TK-TK-BTK. The set remained as 8 vehicles from then.
The 'Coronation' was introduced in 1937, linking the Capitals of England and Scotland in 6 hours (the Flying Scotsman took 7 hours 20 at this time but often loaded 12-16 coaches). As a result of the longer journey time and both services leaving within 30 mins of each other, opposing formations were required and it was decided to build three 8-coach sets, two with Coronation in raised lettering on the side and one plain for use as a spare.
Two beaver-tail Observation Cars were built for use in summer months with seating for 16, though over half the vehicles were actually van space. The 3 sets were formed as 4 articulated pairs and unlike the Silver Jubilee were all open saloon with all seats reserveable and meals at all seats in both classes:
BTO-TO
RT-TO
FO-FO
RT-BTO
A desire to maximise seating saw a pantry removed from each RT giving 3 extra Third Class seats, however this proved to the detriment of the catering service as there was insufficient room for staff to provide the required service and so within 6 months the RTs were rebuilt with 2 pantries a 3 fewer seats.
The West Riding Limited between King's Cross, Leeds and Bradford later in September 1937 using one identical set to the Coronation but with West Riding Limited lettering and no Observation Car.
The unbranded spare set was then used to replace either of the Coronation sets or the West Riding set as necessary.
