Appendix VII: Main Motors and Batteries
For convenience this appendix has been divided into two sections VIIA and VIIB.
- Appendix VIIA covers the HOLLAND to M Classes except for SWORDFISH (1913) and the S, W, F and J Classes, about which some information is given in the relevant chapter dealing with the class.
- The information given in this appendix applies to the boats built by Vickers and may not necessarily apply to vessels of the same class built by HM Dockyards or other Firms.
- (a) All motors were of the open type.
- (b) All motors were built by the Don Works, except for the HOLLAND Class built by the Electric Dynamic Co USA and for VI by Laurence Scott.
- (c) The M Class only was fitted with an auxiliary drive motor.
Appendix VIIB covers all vessels from the H21 to PORPOISE Classes.
All motors up to and including XI were of the open type and from OBERON onwards of the closed type.
- The motor was geared to the propeller shaft to give shaft revolutions of 200 rev/min.
- This would be with overload. At the normal duration of battery discharge at full speed the motor would develop 200 ehp.
- The motors were geared to the propeller shafts to give shaft revolutions of 160 rev/min.
- Type of battery as first fitted.
- In the E Class onwards the battery was split into sections to allow working in series (grouper up) or in parallel (grouper down). The voltage given in this line is with the battery in series. When in parallel the voltage was one half the value given in all cases.
- C21 had an Exide battery - the first change in type of battery.
- The weight varied within individual classes depending on the type of battery fitted.