| Description | Date | Identifier | |
| Letter to Messrs. G. Cussons Ltd. requesting a drawing with dimensions for a Dalby-Watson Optical Indicator and its chain drive. | 28th Jan 1918 | Box 79 \ 3 scan0075 | |
| Confirmation of an order for a Dalby-Watson Optical Indicator, urging no delay. | 28th Jan 1918 | Box 79 \ 3 scan0076 | |
| Letter to Messrs. G. Cusson Ltd. chasing the delivery of an outstanding order for a Dalby Watson Optical. | 8th Feb 1918 | Box 79 \ 3 scan0077 | |
| Letter from G. Cussons Ltd. concerning a print showing an Optical Indicator rigged on an engine base. | 8th Feb 1918 | Box 79 \ 3 scan0078 | |
| Letter and blueprint from Messrs. Cussons for the Dalby-Watson Optical Indicator on the Eagle engine. | 9th Feb 1918 | Box 79 \ 3 scan0079 | |
| Letter from G. Cussons, Ltd. regarding delivery timelines and priority certificates for war work. | 10th Feb 1918 | Box 79 \ 3 scan0080 | |
| Dalby-Watson Optical Indicator, requesting information and instructions for the corresponding rig. | 13th Mar 1918 | Box 79 \ 3 scan0081 | |
| Organization of work for experimental test tackle and special devices. | 6th Apr 1918 | Box 79 \ 3 scan0082 | |
| The handover of an Eagle Engine job and Indicator Diagram Apparatus to Mr. Bailey's department. | 6th Apr 1918 | Box 79 \ 3 scan0083 | |
| Letter from G. Cussons, Ltd. explaining a delay in the delivery of an Optical Indicator due to production pressures. | 13th May 1918 | Box 79 \ 3 scan0084 | |
| Order for a specific S7 Ball Bearing from Messrs Hoffmann for a Dalby-Watson Optical Indicator Apparatus. | 7th Jun 1918 | Box 79 \ 3 scan0085 | |
| Request to produce one set of parts for the Dalby Watson Indicator from a list of drawings. | 14th Jun 1918 | Box 79 \ 3 scan0086 | |
| To Mr. Clarke regarding a delivery delay for a Dalby Watson Optical Indicator from Messrs G Cusson Ltd. | 17th Jun 1918 | Box 79 \ 3 scan0087 | |
| Letter from G. Cussons, Ltd. regarding the delayed delivery of an Optical Indicator due to resources being diverted to aircraft work. | 6th Jun 1918 | Box 79 \ 3 scan0088 | |
| To Mr. Clark in the Experimental Department chasing the delivery of a Dalby-Watson Optical Indicator. | 3rd Jul 1918 | Box 79 \ 3 scan0089 | |
| Acquisition of a Dalby-Watson Optical Indicator from Messrs. Gussons. | 4th Jul 1913 | Box 79 \ 3 scan0090 | |
| Notification regarding the receipt of various ball bearings for Dalby Watson Indicators. | 8th Jul 1918 | Box 79 \ 3 scan0091 | |
| Two photographs of a piece of machinery, one showing it disassembled and the other assembled. | 12th Sep 1914 | Box 79 \ 3 scan0092 | |
| Diagrams from a Dalby-Watson Optical Indicator. | 12th Sep 1914 | Box 79 \ 3 scan0093 | |
| Article from 'The Mechanical Engineer' journal detailing an optical indicator for steam and gas engines. | 13th Mar 1914 | Box 79 \ 3 scan0094 | |
| Confirmation of a telegram inquiring about the Dalby Watson Indicator. | 10th Sep 1918 | Box 79 \ 3 scan0095 | |
| Urgent request for tracings of blueprints for a Dalby Watson Optical Indicator for Mr. Royce. | 11th Sep 1918 | Box 79 \ 3 scan0096 | |
| Letter regarding the delayed delivery of a Dalby Watson Optical Indicator from Messrs. G. Cussons, Ltd. due to urgent war work. | 11th Sep 1918 | Box 79 \ 3 scan0097 | |
| Photographs and diagrams of a Dalby Watson Optical Indicator. | 13th Sep 1918 | Box 79 \ 3 scan0098 | |
| Request for two blueprints of tracings for the Dalby Watson Optical Indicator. | 18th Sep 1918 | Box 79 \ 3 scan0099 | |
| Blueprints for the Dalby Watson Optical Indicator for use on aero engines. | 21th Sep 1918 | Box 79 \ 3 scan0100 | |
| Difficulties encountered with the Daley-Watson Indicator and potential solutions. | 21th Sep 1918 | Box 79 \ 3 scan0101 | |
| Modifying a 'Falcon' engine and sharing information with U.S. aero experts. | 26th Apr 1917 | Box 79 \ 3 scan0102 | |
| Forwarding of illustrations for the Dalby Watson Optical Indicator and an inquiry about its difficulties. | 24th Sep 1918 | Box 79 \ 3 scan0103 | |
| Letter to G. Cussons Ltd regarding difficulties with the Dalby Watson Optical Indicator. | 24th Sep 1918 | Box 79 \ 3 scan0104 | |
| Imperfections of the Dalby-Watson Indicator and a response from Messrs. Cussons. | 15th Oct 1918 | Box 79 \ 3 scan0105 | |
| Follow-up letter from The Cambridge and Paul Instrument Company regarding a quotation for a Collins Micro-Indicator. | 31th Aug 1922 | Box 79 \ 3 scan0106 | |
| Reprint from 'ENGINEERING' magazine describing the Collins Micro-Indicator for high-speed engines. | 9th Jun 1922 | Box 79 \ 3 scan0107 | |
| Extract regarding a change to the speedometer drive on the American model. | 27th Sep 1919 | Box 79 \ 3 scan0108 | |
| The decision to continue right-hand chassis production for America and halt the proposed left-hand drive version. | 31th Oct 1919 | Box 79 \ 3 scan0109 | |
| Requesting two blueprints for a drawing of a speedometer drive for a 3/19 gear box. | 11th Nov 1919 | Box 79 \ 3 scan0110 | |
| Note on experimental numbers taken out for the American Model Chassis. | 19th Nov 1919 | Box 79 \ 3 scan0111 | |
| Modifications to the speedometer drive and reduction gear for the 3/19 gearbox. | 19th Nov 1919 | Box 79 \ 3 scan0112 | |
| Continued document specifying speedometer drive adjustment tolerances and gear shaft lubrication methods. | 19th Nov 1919 | Box 79 \ 3 scan0113 | |
| Providing a status update on experiments related to pistons, starter gear, hand brake, and speedometer drive. | 1st Jun 1920 | Box 79 \ 3 scan0114 | |
| Extract discussing a revised design for a geared speedometer drive. | 3rd Jun 1921 | Box 79 \ 3 scan0115 | |
| New geared speedometer drive from Springfield as a replacement for the existing belt drive. | 25th Jun 1921 | Box 79 \ 3 scan0116 | |
| From Hs. to E. listing items despatched to W.W. | 1st Jul 1921 | Box 79 \ 3 scan0117 | |
| The reduction of studs, washers, and springs on the 40/50 chassis spring drive from 20 to 10. | 5th Nov 1920 | Box 79 \ 3 scan0118 | |
| Reduction of end play tolerance in the spring drive for the 40/50 Chassis to improve engine quietness. | 27th Mar 1924 | Box 79 \ 3 scan0119 | |
| Page 2 of a document discussing play in spring drives and the use of thicker collars. | 27th Mar 1924 | Box 79 \ 3 scan0120 | |
| Requesting detail drawings for the 20 HP Damped Spring Drive. | 3rd Jul 1919 | Box 79 \ 3 scan0121 | |
| Print for a 20 HP Damped Spring Drive. | 23th Jul 1919 | Box 79 \ 3 scan0122 | |
| Receipt of bronze, circlips, and springs from suppliers. | 14th Apr 1920 | Box 79 \ 3 scan0123 | |
| Parts fitted to a Goshawk engine for testing. | 9th Sep 1920 | Box 79 \ 3 scan0124 | |
| Design of the Goshawk Spring Drive & Damping Flywheel, specifically the flywheel stud locking mechanism and the starting dog washer material. | 15th Mar 1921 | Box 79 \ 3 scan0125 | |
| Requesting the production of two sets of a 1-G-1 spring drive to be fitted to G.11, noting it as a high priority job. | 27th May 1927 | Box 79 \ 3 scan0126 | |
| The difficulty of removing the spring drive from the crankshaft, with a suggested modification to the nut. | 1st Sep 1921 | Box 79 \ 3 scan0127 | |
| Modifications to the Goshawk 11 crankshaft spring drive unit to address periodic torsional effects. | 13th Sep 1921 | Box 79 \ 3 scan0128 | |
| Request for a torsional load test on a Goshawk 11 crankshaft and details on its spring drives. | 16th Sep 1921 | Box 79 \ 3 scan0129 | |
| Drawings for a new large type crankshaft pinion spring drive for the Goshawk 11 engine. | 21th Sep 1921 | Box 79 \ 3 scan0130 | |
| Spring drive tests for the Goshawk engine, recommending a separate friction flywheel to overcome crankshaft periods. | 23th Sep 1921 | Box 79 \ 3 scan0131 | |
| Drawing LeC.1458 for the Goshawk 11 spring drive, slipper flywheel, and temporary wheelcase. | 5th Oct 1921 | Box 79 \ 3 scan0132 | |
| Goshawk 11 crankshaft pinion spring drive and slipper flywheel, detailing wheelcase alterations. | 6th Oct 1921 | Box 79 \ 3 scan0133 | |
| The Goshawk 11 crankshaft pinion spring drive, stating that work on Spring Drive LeC.1449 should cease as it is superseded by scheme LeC.1458 with a slipper flywheel. | 8th Oct 1921 | Box 79 \ 3 scan0134 | |
| The Goshawk 11 undershield and a half-time wheelcase. | 12th Oct 1921 | Box 79 \ 3 scan0135 | |
| Technical drawing of a Slipper Flywheel (Front Half). | 21th Mar 1922 | Box 79 \ 3 scan0136 | |
| Investigation into the cause of Goshawk II engine gear rattles due to slack in the spring drive. | 16th Sep 1922 | Box 79 \ 3 scan0137 | |
| Continued note regarding the Drawing Office's agreement to make a plate of a specific shape for the Goshawk-ll. | 18th Dec 1922 | Box 79 \ 3 scan0138 | |
| Potential improvements to valves and spring drives for Goshawk engines. | 18th Dec 1922 | Box 79 \ 3 scan0139 | |
| Design decisions regarding half-time gears, the magneto, and the exhaust valve. | 18th Dec 1922 | Box 79 \ 3 scan0140 | |
| Telegram from R. Royce regarding Goshawk spring drives and valve design modifications. | 18th Dec 1922 | Box 79 \ 3 scan0141 | |
| Typed letter quoting a wire from Mr. Royce about design modifications to the Goshawk engine's spring drives and valves. | 19th Dec 1922 | Box 79 \ 3 scan0142 | |
| Halting the current Goshawk Spring Drive design in favour of a superior new one being sent out shortly. | 27th Dec 1922 | Box 79 \ 3 scan0143 | |
| Improved spring drive for the Goshawk 11 engine, including drawing No.LeC.1665. | 30th Dec 1922 | Box 79 \ 3 scan0144 | |
| Continued report on the design of driving and damping springs for a flywheel and camshaft gear-wheel assembly. | 1st Jan 1923 | Box 79 \ 3 scan0145 | |
| Driving and damping springs for the revised Goshawk 11 spring drive, referencing drawing No.LeC.1666. | 1st Jan 1923 | Box 79 \ 3 scan0146 | |
| Query regarding the load specification for the Goshawk II slipper flywheel spring loading. | 18th Jan 1923 | Box 79 \ 3 scan0147 | |
| Suggestion to permanently rivet together half fan pulley rim pressings for a spring drive before trimming the groove. | 14th Feb 1923 | Box 79 \ 3 scan0148 | |
| Agreeing to the practice of riveting Pulley Rim Pressings before turning for the Goshawk Spring Drive. | 15th Feb 1923 | Box 79 \ 3 scan0149 | |
| Recommending the immediate adoption and standardisation of a new, superior design for the Goshawk Damped Spring Drive. | 26th Apr 1923 | Box 79 \ 3 scan0150 | |
| Friction damping plate working loose on the latest type spring drive for the 20 HP engine, with a suggested fix. | 10th May 1923 | Box 79 \ 3 scan0151 | |
| Revised design for the Goshawk 11 spring drive to overcome issues found during testing. | 2nd Jun 1923 | Box 79 \ 3 scan0152 | |
| Modifications to a crankshaft spring drive, including assembly instructions and associated changes to damper springs and a cooling fan. | 2nd Jun 1923 | Box 79 \ 3 scan0153 | |
| Instruction to increase the number of spring spigots on slipper flywheels for the Goshawk II from 8 to 16. | 2nd Jun 1923 | Box 79 \ 3 scan0154 | |
| Request to produce test sets of slipper flywheel springs for the 'Goshawk II' engine from existing stock due to a delay. | 11th Jun 1923 | Box 79 \ 3 scan0155 | |
| Slipper flywheel clearances for the 20 HP chassis spring drive, covering both serrated and non-serrated types. | 19th Jun 1923 | Box 79 \ 3 scan0156 | |
| Standardisation document for an improved spring drive on chassis parts. | 22th Jun 1923 | Box 79 \ 3 scan0157 | |
| Slight revision to the Goshawk 11 fan pulley and spring drive. | 16th Aug 1923 | Box 79 \ 3 scan0158 | |
| Note detailing the specifications for a standard and an experimental spring for a 20HP spring drive. | 18th Dec 1923 | Box 79 \ 3 scan0159 | |
| Fault with the 20-HP engine spring drive causing noises due to springs binding against back plates. | 23th Jan 1924 | Box 79 \ 3 scan0160 | |
| Alteration to a Bakelite washer thickness for the 20 HP Chassis Spring Drive. | 25th Apr 1924 | Box 79 \ 3 scan0161 | |
| Change in damping springs for a 20 HP Chassis Spring Drive. | 29th Apr 1924 | Box 79 \ 3 scan0162 | |
| Testing and standardising the 20 HP spring drive damping springs. | 27th May 1924 | Box 79 \ 3 scan0163 | |
| From Mr. Royce regarding experiments on road springs. | 5th Mar 1912 | Box 79 \ 3 scan0164 | |
| Mr. Royce's instructions on calculating loads for rear springs. | 5th Mar 1912 | Box 79 \ 3 scan0165 | |
| Requesting characteristic curves for rear springs and discussing variations in their design and friction. | 31th Oct 1913 | Box 79 \ 3 scan0166 | |
| Instructions from Mr Royce to test the rating and behaviour of rear springs across their full range of action. | 4th Nov 1913 | Box 79 \ 3 scan0167 | |
| Tests of standard and special rear springs, giving load per inch of deflection. | 10th Nov 1913 | Box 79 \ 3 scan0168 | |
| Deflection of rear springs, attaching a report with figures to plot a characteristic curve. | 18th Nov 1913 | Box 79 \ 3 scan0169 | |
| Instructions regarding the characteristic curve of rear road springs and their potential shock-damping effect. | 9th Sep 1913 | Box 79 \ 3 scan0170 | |
| Proposal for testing different spring combinations following unsatisfactory results with thin top plates and rolled eyes. | 22th Dec 1913 | Box 79 \ 3 scan0171 | |
| Design and testing of experimental front springs. | 21th Apr 1914 | Box 79 \ 3 scan0172 | |
| Instruction sheet requesting an experiment to determine the Modulus of Elasticity (E) for road springs, including experimental results. | 1st Apr 1914 | Box 79 \ 3 scan0173 | |
| The modulus of elasticity of road springs, with tabulated test data for two different blades. | 18th Apr 1914 | Box 79 \ 3 scan0174 | |
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