| Description | Date | Identifier | |
| Blueprint showing a cross-section of a 25 HP double flywheel bearing. | 16th Aug 1931 | Box 137 \ 4 scan0205 | |
| Engine vibrations, their potential causes like torsion and gas pressure, and analysis methods. | 16th Aug 1931 | Box 137 \ 4 scan0206 | |
| Technical discussion on engine vibrations, mountings, and methods for improving smoothness in 6-cylinder engines. | 16th Aug 1931 | Box 137 \ 4 scan0207 | |
| Engine vibrations, including torsional harmonics and flywheel whirl, and potential solutions. | 16th Aug 1931 | Box 137 \ 4 scan0208 | |
| Engine vibration issues, causes such as torque reactions and flywheel whirl, and potential solutions. | 16th Aug 1931 | Box 137 \ 4 scan0209 | |
| Improving vehicle performance and smoothness through engine, chassis, and body modifications. | 16th Aug 1931 | Box 137 \ 4 scan0210 | |
| Frame rigidity and steering improvements using diagonal steel strips and torque arms. | 17th Feb 1931 | Box 137 \ 4 scan0211 | |
| Technical analysis of piston inertia torque and its effect on engine roughness across various engine types. | 17th Feb 1931 | Box 137 \ 4 scan0212 | |
| Graph comparing piston inertia torque curves for various engine cylinder configurations. | 17th Feb 1931 | Box 137 \ 4 scan0213 | |
| Experiments to reduce engine vibration and booms by modifying the flywheel. | 17th Feb 1931 | Box 137 \ 4 scan0214 | |
| Experiments with lightened flywheels and extra bearings to reduce engine roughness and vibrations on various models. | 17th Feb 1931 | Box 137 \ 4 scan0215 | |
| Comparison of inertia torques and crankshaft stiffness between 8-cylinder and 6-cylinder engines. | 17th Feb 1931 | Box 137 \ 4 scan0216 | |
| Alternative engine mounting scheme to reduce vibrations and booms. | 17th Feb 1931 | Box 137 \ 4 scan0217 | |
| Rescheduling a test concerning Phantom II Vibrations and Booms. | 18th Feb 1931 | Box 137 \ 4 scan0218 | |
| Investigations into Phantom car engine vibrations and proposed testing methods. | 20th Feb 1931 | Box 137 \ 4 scan0219 | |
| Engine design modifications and testing results for prototypes Phantom I and P.2. | 21th Feb 1931 | Box 137 \ 4 scan0220 | |
| Telegram discussing engine vibration issues at twelve hundred RPM and proposed modifications to the clutch, flywheel, and balance weight. | 21th Feb 1931 | Box 137 \ 4 scan0221 | |
| Telegram received by telephone discussing a decision on periodicity, torsional vibration, and damper design. | 4th Jun 1929 | Box 137 \ 4 scan0222 | |
| Telegram received by telephone form with a short handwritten message. | 4th Jun 1929 | Box 137 \ 4 scan0223 | |
| Testing and investigation into the cause and potential cures for 'booms and vibrations' on the Phantom II model. | 23th Feb 1931 | Box 137 \ 4 scan0224 | |
| Chassis frame jellying, Diamond engine mounting tests, and faults on left-hand drive cars for the USA market. | 23th Feb 1931 | Box 137 \ 4 scan0225 | |
| Unresolved issues with left-hand drive cars, including vibrations, shock absorbers, and increased engine compression ratio. | 23th Feb 1931 | Box 137 \ 4 scan0226 | |
| Cable transcript detailing suggestions for a 'Phantom Period' test regarding flywheel vibration and damper design. | 26th Feb 1931 | Box 137 \ 4 scan0227 | |
| From Le Canadel discussing potential improvements to car 18-EX, also known as China 4. | 23th Feb 1931 | Box 137 \ 4 scan0228 | |
| Designing a lighter and stiffer flywheel for Phantom experiments. | 23th Feb 1931 | Box 137 \ 4 scan0229 | |
| Car vibrations, crankshaft balance, and flywheel design in response to Mr. Gills' memo. | 25th Feb 1931 | Box 137 \ 4 scan0230 | |
| Mr. Grylls' findings on 12-cylinder engines at various angles and comparing them to Maybach and Lion engines. | 26th Feb 1931 | Box 137 \ 4 scan0231 | |
| New engine mounting design to address vibrations and chassis wobbles. | 27th Feb 1931 | Box 137 \ 4 scan0232 | |
| Diagram illustrating the movement of an engine linkage and mounting system. | 27th Feb 1931 | Box 137 \ 4 scan0233 | |
| Preliminary scheme for a ball bearing at the back of the flywheel to address vibrations. | 27th Feb 1931 | Box 137 \ 4 scan0234 | |
| Causes and solutions for car body booming and chassis vibrations. | 28th Feb 1931 | Box 137 \ 4 scan0235 | |
| Chassis and body vibration issues, comparing different body types and suggesting improvements to dampers. | 2nd Mar 1931 | Box 137 \ 4 scan0236 | |
| Tests on a Phantom II model to address a 'boom' noise by trying a stiffer flywheel and crankshaft flange. | 2nd Mar 1931 | Box 137 \ 4 scan0237 | |
| Blueprint of a Crankshaft Stiff Flange for a 40/50 model. | 2nd Mar 1931 | Box 137 \ 4 scan0238 | |
| Blueprint drawing of a stiffened flywheel, part PII, showing a cross-section and detail for a nut recess. | 18th Dec 1930 | Box 137 \ 4 scan0239 | |
| Standardisation of cotton 'A' fabric linings for Torque Reaction Dampers on the 20/25 HP. | 18th Dec 1930 | Box 137 \ 4 scan0240 | |
| Costs and logistics for fitting a new part to a chassis. | 3rd May 1931 | Box 137 \ 4 scan0241 | |
| Causes and prevention of resonant body booming noises in vehicles. | 6th Mar 1931 | Box 137 \ 4 scan0242 | |
| Diagnosis of booming and vibration issues by swapping chassis and bodies between different cars. | 6th Mar 1931 | Box 137 \ 4 scan0243 | |
| 'boom' or vibration issue in 12-cylinder cars at high speeds, comparing performance unfavourably with competitor Bentley models. | 7th Mar 1931 | Box 137 \ 4 scan0244 | |
| Diagnosis and potential solutions for engine and body vibrations, known as 'booms'. | 7th Mar 1931 | Box 137 \ 4 scan0245 | |
| Potential engine and chassis improvements to reduce impulses and noise. | 7th Mar 1931 | Box 137 \ 4 scan0246 | |
| 'booming of bodies' and requesting details on Bentley coachwork for comparison. | 7th Mar 1931 | Box 137 \ 4 scan0247 | |
| To W.J. Iden Esq. requesting his views on a suggestion from the National Omnibus and Transport Co. regarding Chassis No. 119-GN. | 11th Mar 1931 | Box 137 \ 4 scan0248 | |
| Letter from The National Omnibus & Transport Co. Ltd. complaining about a booming noise in a Phantom II chassis. | 6th Mar 1931 | Box 137 \ 4 scan0249 | |
| Letter discussing alterations to the exhaust system to eliminate a noise on Chassis 119-GN. | 11th Mar 1931 | Box 137 \ 4 scan0250 | |
| Introducing a thicker crankshaft flange for the Phantom II to address 'booming bodies'. | 11th Mar 1931 | Box 137 \ 4 scan0251 | |
| Investigation into the cause of booms and vibrations in the Phantom II vehicle. | 11th May 1931 | Box 137 \ 4 scan0252 | |
| Investigation into an engine 'boom' noise, testing crankshafts, balance weights, flywheels and engine mountings on Phantom I and II models. | 11th Mar 1931 | Box 137 \ 4 scan0253 | |
| Suggesting the isolation of the steering box with a rubber slab to reduce engine vibration on model 25-EX. | 13th Mar 1931 | Box 137 \ 4 scan0254 | |
| Opinions on chassis vibrations, bodywork, and engine mounting for 'booming cars'. | 13th Mar 1931 | Box 137 \ 4 scan0255 | |
| Methods to reduce torsional vibrations and booming, focusing on engine mounting and frame design comparisons. | 13th Mar 1931 | Box 137 \ 4 scan0256 | |
| Issues of engine mounting, vibration, and noise in different car models, outlining points for investigation. | 14th Mar 1931 | Box 137 \ 4 scan0257 | |
| Telegram discussing a flywheel issue, its cause, and suggested solutions involving a tie bar and weights. | 14th Mar 1931 | Box 137 \ 4 scan0258 | |
| Cover sheet for information on a diamond mounting and torsionally rigid frame, independent of the engine. | 14th Mar 1933 | Box 137 \ 4 scan0259 | |
| Technical memo discussing the source and potential cures for body booms and vibrations in a vehicle. | 14th Mar 1931 | Box 137 \ 4 scan0260 | |
| Engine vibration, frame weakness, and potential solutions involving engine mounting and body isolation, referencing the 6-litre Bentley. | 16th Mar 1931 | Box 137 \ 4 scan0261 | |
| Telegram discussing chassis rigidity and vibration issues, suggesting modifications to the frame. | 16th Mar 1931 | Box 137 \ 4 scan0262 | |
| Typed copy of a telegram regarding experiments on flywheel improvements and different engine mounting systems. | 16th Mar 1931 | Box 137 \ 4 scan0263 | |
| Modifications for a car, referencing issues found on a similar model, and deciding on communication strategy. | 18th Mar 1931 | Box 137 \ 4 scan0264 | |
| Testing and troubleshooting booming and air pressure issues in an exhibition car body on chassis No. 147-GY. | 18th Mar 1931 | Box 137 \ 4 scan0265 | |
| Investigation of 'boom periods' on a Phantom II for Mr. Davis by swapping car bodies. | 18th Mar 1931 | Box 137 \ 4 scan0266 | |
| Engine mounting and frame design to mitigate torque vibrations, with comparisons to Bentley and Hispano. | 18th Mar 1931 | Box 137 \ 4 scan0267 | |
| Engine mounting, frame rigidity, vibration issues, and cylinder configurations. | 19th Mar 1931 | Box 137 \ 4 scan0268 | |
| Experimental tests to fix the 'Phantom booms' complaint by modifying engine and body mountings. | 19th Mar 1931 | Box 137 \ 4 scan0269 | |
| Telegram detailing experimental tests to resolve a 'Phantom Booms' complaint. | 19th Mar 1931 | Box 137 \ 4 scan0270 | |
| Phantom II, explaining why a new body is not being fitted to a secondhand chassis and that a new chassis is being supplied to Thrupps. | 20th Mar 1931 | Box 137 \ 4 scan0271 | |
| Experimental results to reduce engine booming in Phantom II & 25 HP cars, focusing on engine modifications and the 'Diamond' engine mounting. | 21th Mar 1931 | Box 137 \ 4 scan0272 | |
| Engine mounting experiments and issues for various models, including the 25 HP, 40/50, and P.II. | 21th Mar 1931 | Box 137 \ 4 scan0273 | |
| Analysis of vibration, steering shocks, and booming issues, comparing Phantom I and Phantom II models. | 21th Mar 1931 | Box 137 \ 4 scan0274 | |
| Analysis of chassis boom issues related to different body types and mounting conditions. | 21th Mar 1931 | Box 137 \ 4 scan0275 | |
| Chassis variations, flywheel whirling, and engine booms on various models. | 21th Mar 1931 | Box 137 \ 4 scan0276 | |
| Results of various experimental tests on the power unit, engine mountings, and chassis features to resolve issues like 'booms' and vibrations. | 21th Mar 1931 | Box 137 \ 4 scan0277 | |
| Page 2 of a report detailing investigations into vehicle 'boom' and vibration issues. | 23th Mar 1931 | Box 137 \ 4 scan0278 | |
| Cure for a booming sound in cars by isolating the dash and steering column using rubber mounts. | 23th Mar 1931 | Box 137 \ 4 scan0279 | |
| Arrangements to fix booming and drumming troubles in demonstration cars. | 23th Mar 1931 | Box 137 \ 4 scan0280 | |
| Arranging for a Phantom II car (112-GN) to be sent for urgent repairs to address booming and drumming noises. | 24th Mar 1931 | Box 137 \ 4 scan0281 | |
| Resolving body boom issues and a customer complaint on a Phantom II. | 25th Mar 1931 | Box 137 \ 4 scan0282 | |
| Proposed arrangement for isolating a silencer from a troublesome chassis. | 25th Mar 1931 | Box 137 \ 4 scan0283 | |
| Technical analysis of the causes and mechanics of 'booming' vibrations in cars. | 25th Mar 1931 | Box 137 \ 4 scan0284 | |
| Proposal for using the car's scuttle and dash as a horn amplifier, based on the principles of diaphragm speakers. | 25th Mar 1931 | Box 137 \ 4 scan0285 | |
| Analysis of resonant vibrations and booming noises in vehicle bodies, comparing Phantom I and Phantom II chassis. | 25th Mar 1931 | Box 137 \ 4 scan0286 | |
| Analysis of frame rigidity and the causes of resonant booming in car bodies, focusing on roof construction and passenger cabin shape. | 25th Mar 1931 | Box 137 \ 4 scan0287 | |
| Clarifying the author's non-involvement in the investigation into 'Booming Cars' on the P.2. & 20/25HP models. | 25th Mar 1931 | Box 137 \ 4 scan0288 | |
| Experiments with engine mounts, flywheel balancing, and frame stiffness to reduce engine vibration and body booms. | 25th Mar 1931 | Box 137 \ 4 scan0289 | |
| Recommendation on curing engine trouble by addressing vibrations at the source and using thicker rubber mountings. | 26th Mar 1931 | Box 137 \ 4 scan0290 | |
| Telegram discussing body vibrations, bonnet knocking, and proposed engine improvements for a twelve-cylinder model. | 26th Mar 1931 | Box 137 \ 4 scan0291 | |
| 'booming complaint' on car 147-GY for a Mr. Davies. | 28th Mar 1931 | Box 137 \ 4 scan0292 | |
| Customer satisfaction test drive and feedback for Chassis No. 147-GY. | 18th Mar 1931 | Box 137 \ 4 scan0293 | |
| The second page of a typed document discussing collaborative work on a job. | 31th Mar 1931 | Box 137 \ 4 scan0294 | |
| Investigation into 'body boom' issues on Phantom II car 27-EX, involving a new crankshaft and balance weights. | 31th Mar 1931 | Box 137 \ 4 scan0295 | |
| Investigation into 'body booms' and the results of removing rear engine feet as a solution. | 31th Mar 1931 | Box 137 \ 4 scan0296 | |
| From Hives to Royce reporting issues with a flywheel, balance weights, and an epicyclic gearbox. | 31th Mar 1931 | Box 137 \ 4 scan0297 | |
| Copy of a letter discussing P.2 engine vibrations, periods, and mounting. | 31th Mar 1931 | Box 137 \ 4 scan0298 | |
| Engine mounting strategies, frame stiffness, and the prevention of torsional twisting. | 31th Mar 1931 | Box 137 \ 4 scan0299 | |
| Chassis vibrations, competition from Hispano and Bentley, and brand pricing strategy. | 1st Apr 1931 | Box 137 \ 4 scan0300 | |
| Telegram received by telephone discussing engine vibration, pinion issues and the need for brake control. | 1st Apr 1931 | Box 137 \ 4 scan0301 | |
| Copy of a telegram concerning engine high-speed vibration and crankshaft torsional harmonics. | 1st Apr 1931 | Box 137 \ 4 scan0302 | |
| Proposed palliative measures to address excessive 'jellying' and road shocks in cars. | 2nd Apr 1931 | Box 137 \ 4 scan0303 | |
| Analysis of chassis booming and torque reaction, with proposals for future solutions including diamond engine mounting. | 2nd Apr 1931 | Box 137 \ 4 scan0304 | |
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