British engines

[AM]

Hi all

It's a designation system (similar SBAC designations) or ... ???

ALeM Alvis Leonides Major ASA Armstrong Siddeley Adder AS.DM SAMD Armstrong Siddeley Double Mamba ASMa Armstrong Siddeley Mamba ASP Armstrong Siddeley Python ASSa Armstrong Siddeley Sapphire ASSn Armstrong Siddeley Snarler AsSt Armstrong Siddeley Stentor --> BSt ASV Armstrong Siddeley Viper BOl Bristol Siddeley Olympus BOn Bristol Siddeley Orion BOr Bristol Siddeley Orpheus BPh Bristol Siddeley Phoebus BPr Bristol Siddeley Proteus BSt Bristol Siddeley Stentor BT Bristol Siddeley Thor BTh Bristol Siddeley Theseus BnN Bristol Siddeley Nimbus DGt de Havilland Ghost DGn de Havilland Goblin DGJ de Havilland Gyron Junior DGy de Havilland Gyron DSpe de Havilland Spectre DSpeD de Havilland Double Spectre DSpr de Havilland Sprite MVSa Metropolitan-Vickers Sapphire --> ASSa NEl Napier Eland NGa Napier Gazelle NNa Napier Naiad NNm Napier Nomad NOr Napier Oryx NSc Napier Scorpion NScD Napier Double Scorpion NScT Napier Triple Scorpion RA Rolls-Royce Avon RCo Rolls-Royce Conway RD Rolls-Royce Derwent RDa Rolls-Royce Dart RN Rolls-Royce Nene RSp Rolls-Royce Spay RSr Rolls-Royce Soar RTa Rolls-Royce Tay RTy Rolls-Royce Tyne

 

[Apophenia]

These were Ministry of Supply designations for individual engine types. Some other MS designations were ASA. (Armstrong-Siddeley Adder); ASV. (Armstrong-Siddeley Viper); ASSn. (Armstrong-Siddley Snarler); BPh. (Bristol Phoebus); BPr. (Bristol Proteus); BT. (Bristol Thor); RN. (Rolls-Royce Nene); etc.

 

[lleu]

R.M. Rolls-Royce Merlin
R.G. Rolls-Royce Griffon

Merlin XX - RM 3SM, Merlin 45 - RM 5S, Griffon 100 - RG 3SML

What is the meaning of last letters in designations? Small/Middle/Large supercharger speed?