Midland Red Buses of the 1920s

SOS S was originally "Standard SOS"

Model	SOS S
Details	Single deck with driver's seat within the saloon 4-cylinder petrol engine 32 seats
Total Number	Introduced	Notes
8	1923	Brush bodywork with front entrance on Tilling chassis
10	1923	Davidson charabanc bodywork on Tilling chassis
113	1923	Brush, Carlyle or Ransomes bodywork with front entrance
7	1923	Davidson charabanc bodywork

SOS FS probably stood for "Forward Steering" because they were the first half cab buses although "Future Standard" also has some merit. All the subsequent models had half cabs although, after the war, the half cab was built into the main superstructure.

Model	SOS FS
Details	Single deck with half cab 4-cylinder petrol engine 34 seats
Total Number	Introduced	Notes
2	1925	Carlyle bodywork with front entrance
18	1926	Davidson charabanc bodywork
63	1926	Brush bodywork with front entrance

SOS Q originally stood for "Queen", although two were used as demonstrators and named "Quality" and "Quantity". The SOS QL was the first Midland Red model with a low chassis. All subsequent models were built on a low chassis.

Model	SOS Q & QL
Details	Single deck with front entrance 4-cylinder petrol engine 37 seats
Total Number	Introduced	Notes
109	1926	Brush bodywork
1	1928	Carlyle bodywork
173	1928	Brush or Ransomes bodywork and low chassis (QL)

SOS QC stood for "Queen Charabanc".

Model	SOS QC
Details	Single deck with Carlyle charabanc bodywork and high chassis 4-cylinder petrol engine 30 seats
Total Number	Introduced	Notes
14	1927

SOS QLC was the low chassis version of the SOS QC.

Model	SOS QLC
Details	Single deck with Short Bros charabanc bodywork and low chassis 29 seats
Total Number	Introduced	Notes
15	1928	4-cylinder petrol engine
48	1929	6-cylinder petrol engine

SOS M stood for SOS "Madam".

Model	SOS M
Details	Single deck with front entrance and Brush, Carlyle or Ransomes bodywork 34 seats
Total Number	Introduced	Notes
49	1929

SOS XL probably stood for SOS "Excel" or "Excelsior". The class was not a success and all were converted to MM 6-cylinder buses in 1930.

Model	SOS XL
Details	Coach with Brush or Carlyle bodywork 30 seats
Total Number	Introduced	Notes
50	1929

SOS MM probably stood for "Modified Madam", but could have also been "Modernised Madam".

Model	SOS MM
Details	Single deck with front entrance and Ramsomes bodywork 34 seats
Total Number	Introduced	Notes
20	1929	4-cylinder petrol engine 1930: reclassified as SOS IM4 with new Short Bros bodies and revised registration numbers
60	1929	6-cylinder petrol engine, some with Carlyle bodywork