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).
Series of boat trials, including propeller changes, machinery inspections, and performance issues.
| Identifier | ExFiles\Box 174\5\ img211 | |
| Date | 5th June 1930 guessed | |
| -3- No.3 Steel Propeller was then fitted 16" dia 17¾" pitch, and in the evening of the same day a further trial was made (the first trial on the speed course giving a speed of 109 m.p.h.) On the second lap one blade of the propeller broke and the boat was towed back to the slipway. Engine r.p.m. 1800 to 1850. Examination of the machinery showed that no damage had been done due to this. The stern tube rubber bearing bush had become unscrewed and the stern tube roller bearing housing had partly rotated. The engines did not appear to have suffered in any way and the transmission was otherwise in good order. It is worthy of note that no damage had been done to either hull or transmission through the sudden increase of loads due to the breaking of the propeller, causing extra strains on the machinery throughout. The rubber bearing and roller bearing housing were soon adjusted and No.4 Bronze propeller was fitted 16" dia. x 16" pitch. A further trial was made on Wednesday, after another inspection of hull and machinery, when everything was found to be in order. During the run it was noticed that the forward part of the boat was filling up with water. The engines were stopped, a preliminary examination made, and the boat was brought back under its own power to the slipway. On examination the cause of the water leak was traced to the excessive pressure produced by the forward scoop causing water to be forced out of the stern gland through vent holes provided for that purpose. Engines and transmission gear found to be quite in order, but the propeller blades had deformed. A speed of 101 and 103 m.p.h. was recorded on this trial. Engines r.p.m. 1800 and 1900. This pressure was relieved on subsequent runs by opening a by-pass valve originally fitted to this water system for relieving this pressure. On the Thursday June 12th a fifth run was made with No.1 Propeller, the engines and transmission gear and hull were previously inspected and found to be in good order. After running for approximately two minutes and before finally attaining planning speed the engines revved up to 2850 r.p.m. due to a propeller blade snapping off. An inspection after this showed that no damage whatever had taken place. contd: | ||