From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Design alterations for the 'Goshawk I and II' silencer system.
| Identifier | ExFiles\Box 48\4\ Scan155 | |
| Date | 11th March 1921 | |
| To DA.{Bernard Day - Chassis Design} from E.{Mr Elliott - Chief Engineer} Copy to Co. MCR. HS.{Lord Ernest Hives - Chair} DY.{F R Danby} MPG. X.1238 / X.35/8 RE "GOSHAWK I and II" - SILENCER The designs in connection with the silencing system will apply in principle to both "Goshawk I" and II. Referring to N. scheme 684, would you kindly note the following alterations which Mr. Royce would like made :- (1) Mr. Royce would like you to alter the shape of the bracket from that previously asked for. The new shape should be as in sketch, namely, a complete four-sided plate with four holes punched so as to leave diagonals for stiffening. [Sketch with text] CUT ANGLE PLATES AWAY THUS (2) The cross tubes brazed into the cross member of the frame should be made considerably thinner, so as to be more equivalent to the strength of the bolts used, and thus avoid carrying excessive weight about on the chassis. (3) Two 1/4" bolts should be used for attaching the bracket to the cross member, and they should be placed the other way round so that the plain part near the head carries the bracket, and not the threaded portion. (4) Two 1/4" bolts should be used for attaching the bracket to the silencer instead of the rivets shewn. (5) Four rivets should be used for each angle plate instead of seven on the silencer body, and the portions of the angles carrying the rivets can be shortened .3 at each side, leaving the pitch of the rivets about .875. Referring to N. scheme 686:- (6) The in-coming pipe from the engine, and the swan-neck pipe should both be reduced in diameter from 1 3/4" to 1 1/4". This will necessitate some slight redesigning of the union to the manifolds on the engine, and the fish-tail outlet on the swan-neck pipe should be correspondingly reduced. (7) The internal diaphragms of the silencer should be made spherical in shape, about .9 deep in the middle, with the spheres bulging towards the rear. (Contd.) | ||