| Description | Date | Identifier | |
| Comparison of chromium plating with nitrogen hardening, discussing issues of hardness, adherence, and cracking. | 22th Nov 1928 | Box 30 \ 6 Scan063 | |
| Methods to improve spring lubrication on the 'SS' model going to France. | 11th Dec 1928 | Box 30 \ 6 Scan064 | |
| Micro-examination and mechanical test report on cadmium-plated small screwed parts. | 13th Dec 1928 | Box 30 \ 6 Scan065 | |
| Test results and analysis of cadmium plating on test pieces, focusing on fracture angles and potential causes of failure. | 14th Dec 1928 | Box 30 \ 6 Scan066 | |
| Cadmium plating inducing brittleness in small screwed parts and proposing a special heat treatment. | 14th Dec 1928 | Box 30 \ 6 Scan067 | |
| Failures and further testing related to cadmium plating on small screwed parts. | 17th Dec 1928 | Box 30 \ 6 Scan068 | |
| Material embrittlement during the cadmium plating process and the necessity of post-plating heat treatment. | 19th Dec 1928 | Box 30 \ 6 Scan069 | |
| The re-testing of cadmium plated small screwed parts to determine the angle of breakdown and check for embrittlement. | 20th Dec 1928 | Box 30 \ 6 Scan070 | |
| Micro-examination report on failed cadmium plated small screwed parts, detailing chemical composition and hardness. | 18th Jan 1929 | Box 30 \ 6 Scan071 | |
| Photomicrograph showing the microstructure of a material at 300x magnification. | 29th Nov 1928 | Box 30 \ 6 Scan072 | |
| Instructions for fitting new front and rear springs to car 23-EX, with specified loadings and treatment procedures. | 23th Apr 1929 | Box 30 \ 6 Scan073 | |
| Covering memo discussing correspondence and replies regarding a report on radiator chrome plating. | 23th Apr 1929 | Box 30 \ 6 Scan074 | |
| Chassis alteration no. 3 regarding radiator chrome plating, comparing cost, appearance, and weight of different radiator constructions. | 10th Apr 1929 | Box 30 \ 6 Scan075 | |
| Advantages of loose-shell construction and the market demand for automatic shutters and chromium plating. | 26th Apr 1929 | Box 30 \ 6 Scan076 | |
| Chassis alteration no. 8 dealing with radiator chrome plating. | 26th Apr 1929 | Box 30 \ 6 Scan077 | |
| Urgent internal memo requesting various sets of leaf springs to be cadmium plated and grooved for several cars. | 29th May 1929 | Box 30 \ 6 Scan078 | |
| Letter received from the Chrome Process Syndicate Ltd. about chromo-plating samples. | 18th Sep 1929 | Box 30 \ 6 Scan079 | |
| Letter from Chromo Process Syndicate Ltd. offering to chromium plate samples free of charge for testing. | 14th Aug 1929 | Box 30 \ 6 Scan080 | |
| Cancelling instructions for chromium plating 'T' Section parts for a 20-HP chassis. | 4th Nov 1929 | Box 30 \ 6 Scan081 | |
| Appearance of chromium plating compared to Staybrite steel. | 4th Nov 1929 | Box 30 \ 6 Scan082 | |
| Report discussing material and plating changes for parts, including trials on brass and Staybrite for bonnet hinges. | 14th Nov 1929 | Box 30 \ 6 Scan083 | |
| Instructions for the experimental building of 20 HP and 40/50 HP chassis with modified chromium and Staybrite finishes. | 5th Nov 1929 | Box 30 \ 6 Scan084 | |
| Standardisation, cost, and quality of chromium plating for radiators, chassis and other fittings. | 11th Nov 1929 | Box 30 \ 6 Scan085 | |
| Decision on an alternative for chromium plating, fitting it to external parts only, leaving interior parts with a nickel silver finish. | 13th Nov 1929 | Box 30 \ 6 Scan086 | |
| Investigation into a new chromium plating process and its proposed standardisation for external car parts. | 14th Nov 1929 | Box 30 \ 6 Scan087 | |
| Instruction to change from close plating to a new electro-plating process for Phantom II & 20/25 HP chassis parts for a 10,000-mile test. | 17th Feb 1930 | Box 30 \ 6 Scan088 | |
| Extract from Mr. Platford's report on the Spanish Grand Prix, concerning issues with front engine guards. | 17th Sep 1914 | Box 30 \ 6 Scan089 | |
| Requesting approval for an immediate alteration to the Front Engine Guard, as detailed in Proposal Sheet No. 24. | 10th Nov 1928 | Box 30 \ 6 Scan090 | |
| Proposal letter for a new front engine guard design to address cracking issues. | 30th Oct 1923 | Box 30 \ 6 Scan091 | |
| Complaints of mud and water penetrating the side engine guards on the 20-HP model. | 9th Dec 1926 | Box 30 \ 6 Scan092 | |
| Letter from Melbourne complaining about mud ingress into the engine bay of New Phantom and 20 HP cars. | 10th Oct 1928 | Box 30 \ 6 Scan093 | |
| The effectiveness of Phantom engine guards in preventing mud ingress, comparing driving conditions in France and Australia. | 12th Nov 1928 | Box 30 \ 6 Scan094 | |
| Performance of Phantom engine guards and potential improvements for different road conditions. | 15th Nov 1928 | Box 30 \ 6 Scan095 | |
| Modifications to the Peregrine engine side guards and a new sump design. | 18th Nov 1932 | Box 30 \ 6 Scan096 | |
| Design considerations for Peregrine Undersheets and proposing a trial set. | 8th Mar 1933 | Box 30 \ 6 Scan097 | |
| Modification to the Peregrine engine's undersheets. | 3rd May 1933 | Box 30 \ 6 Scan098 | |
| Progress memo regarding design issues with the 3.5 litre Bentley, specifically the Undersheet. | 3rd May 1933 | Box 30 \ 6 Scan099 | |
| Sending the complete design for Bensport engine and gearbox undersheets and suggesting a trial set be made. | 4th May 1933 | Box 30 \ 6 Scan100 | |
| Modifications and production of Bentley undershields for a test chassis. | 22th Jun 1933 | Box 30 \ 6 Scan101 | |
| Confirming a proposal to manufacture the Bentley Side Lever Guard in aluminium, with a modification to prevent material crushing. | 26th Jun 1933 | Box 30 \ 6 Scan102 | |
| Comparison of brake performance for Continental Touring versus standard use. | 16th Jul 1914 | Box 30 \ 6 Scan103 | |
| Instructions regarding brake performance issues, including wheel lock-up and rubbing, observed during trials in Austria. | 16th Jul 1914 | Box 30 \ 6 Scan104 | |
| Standardisation of oil retaining baffles in rear axle tubes to prevent leakage onto the rear brakes. | 6th May 1920 | Box 30 \ 6 Scan105 | |
| Distributing standardisation sheets for several experiments. | 27th May 1920 | Box 30 \ 6 Scan106 | |
| Standardisation of a modified lubrication system for rear brake actuating shafts. | 8th Oct 1931 | Box 30 \ 6 Scan107 | |
| Form for the standardization of chassis parts, detailing the cost of jigs and tools. | 27th Nov 1923 | Box 30 \ 6 Scan108 | |
| Ergonomic positioning and dimensions of the side brake lever. | 6th Jul 1921 | Box 30 \ 6 Scan109 | |
| Sending the print G.2902 for the X.3458 rear hub and double brake. | 19th May 1919 | Box 30 \ 6 Scan110 | |
| Telegram confirmation from Royce to Hives regarding an experiment on how to keep oil off brakes. | 3rd Apr 1919 | Box 30 \ 6 Scan111 | |
| Potential for experimenting with front brakes and analyzing existing brake system performance. | 8th Aug 1921 | Box 30 \ 6 Scan112 | |
| Tyre pressures, braking performance, and a comparison with other vehicle braking systems. | 4th Aug 1921 | Box 30 \ 6 Scan113 | |
| Defects of a current brake system and considering the implementation of front wheel brakes. | 11th Feb 1920 | Box 30 \ 6 Scan114 | |
| Front-wheel braking and the acquisition of competitor cars like Hispano, Ballot and Duesenberg for analysis. | 4th Aug 1921 | Box 30 \ 6 Scan115 | |
| From Mr. Royce detailing urgent torsion and fracture tests for the front axle system on the 40/50 HP chassis. | 28th Oct 1921 | Box 30 \ 6 Scan116 | |
| Suitability of Perrot and Hotchkiss front wheel brake systems. | 11th Nov 1921 | Box 30 \ 6 Scan117 | |
| Suitability of Perrot and Hotchkiss front wheel brake systems. | 3rd Nov 1921 | Box 30 \ 6 Scan118 | |
| Arguing that the importance of front wheel brakes has been over-estimated compared to other design priorities. | 9th Nov 1921 | Box 30 \ 6 Scan119 | |
| Delays with the application of front wheel brakes, the 'Swallow' project, and proposed schemes for a servo system. | 22th Nov 1921 | Box 30 \ 6 Scan120 | |
| Technical description of a proposed compressed air-assisted braking system. | 22th Nov 1921 | Box 30 \ 6 Scan121 | |
| Servo drum and free wheel designs for a braking system, and progress on the 'Swallow' and 'Goshawk 11' chassis. | 19th Sep 1927 | Box 30 \ 6 Scan122 | |
| Inter-office letter discussing the problems and reasons against implementing four-wheel brakes. | 21th Dec 1921 | Box 30 \ 6 Scan123 | |
| Letter arguing against certain brake designs, citing issues with Hotchkiss drive and steering in winter conditions. | 14th Dec 1922 | Box 30 \ 6 Scan124 | |
| New arrangement for side change levers and a servo-assisted gearbox for front wheel brakes. | 14th Dec 1922 | Box 30 \ 6 Scan125 | |
| Advising on the adoption of left-hand steering and four-wheel brakes for American cars. | 7th Dec 1922 | Box 30 \ 6 Scan126 | |
| Recent serious car accidents involving rival makes, particularly along the road to Nice. | 9th Mar 1923 | Box 30 \ 6 Scan127 | |
| Policy on front wheel brakes in response to a report from Mr. Hives. | 23th Oct 1923 | Box 30 \ 6 Scan128 | |
| Front wheel brakes, discussing the cause of 'jaggers' and proposing modifications to the brake action, springs, and dampers. | 3rd Oct 1923 | Box 30 \ 6 Scan129 | |
| Improvements and concerns for vehicle braking and steering systems. | 1st Nov 1923 | Box 30 \ 6 Scan130 | |
| Report by a motoring correspondent on speed and stopping distance tests for four-wheel brakes fitted to a Bentley car. | 1st Nov 1923 | Box 30 \ 6 Scan131 | |
| Table comparing servo torque multiplication data for the 40/50, 20/25, and Peregrine models. | 8th Nov 1933 | Box 30 \ 6 Scan132 | |
| Request for detailed braking specifications of an 8-cylinder Isotta-Fraschini car for comparison purposes. | 8th Nov 1923 | Box 30 \ 6 Scan133 | |
| Development and issues of a semi-servo brake system, particularly concerning stiff front springs and a proposed torque member solution. | 21th Nov 1923 | Box 30 \ 6 Scan134 | |
| Proposed modifications for a four-wheel brake and suspension system. | 22th Nov 1923 | Box 30 \ 6 Scan135 | |
| How to measure pull to identify unnecessary friction in the four-wheel brake mechanism. | 27th Nov 1923 | Box 30 \ 6 Scan136 | |
| Proposal for experimental alterations to the four-wheel braking system. | 27th Nov 1923 | Box 30 \ 6 Scan137 | |
| Modifications to the braking system, specifically regarding 'servo' action and shoe design. | 28th Nov 1923 | Box 30 \ 6 Scan138 | |
| Brake performance testing parameters and proposed shoe designs. | 28th Nov 1923 | Box 30 \ 6 Scan139 | |
| From DA to HS about the delay in four-wheel brake designs pending experimental results. | 1st Dec 1923 | Box 30 \ 6 Scan140 | |
| Scheme for taking up clearance in rear brakes by rotating the servo with foot pressure. | 12th Jul 1923 | Box 30 \ 6 Scan141 | |
| Braking systems, detailing issues with pedal pressure and proposing an alternative servo scheme. | 1st Jan 1924 | Box 30 \ 6 Scan142 | |
| Servo efficiency and brake pressure modifications to achieve more equal braking. | 11th Jan 1924 | Box 30 \ 6 Scan143 | |
| The causes and elimination of brake jaggers. | 12th Jul 1923 | Box 30 \ 6 Scan144 | |
| Modifications and tests to diagnose braking and steering issues, specifically 'jaggers'. | 1st Jan 1924 | Box 30 \ 6 Scan145 | |
| Front brake effectiveness, steering faults, and brake rig testing. | 12th Jul 1923 | Box 30 \ 6 Scan146 | |
| Issues with steering pivot pins and riveted brake dust covers, and plans for testing a car with new front springs and servo. | 11th Jan 1924 | Box 30 \ 6 Scan147 | |
| Diagram showing the arrangement of Hispano four-wheel brakes. | 1st Jan 1924 | Box 30 \ 6 Scan148 | |
| Schematic diagram of the standard arrangement for four-wheel brakes on a 40-50 model, including modifications. | 1st Jan 1924 | Box 30 \ 6 Scan149 | |
| Calculation of the effective pressure on the rear brakes for the Standard 40-50 RR and Goshawk models. | 15th Jan 1924 | Box 30 \ 6 Scan150 | |
| Comparing the performance of different brake lining materials, specifically Halo and Ferodo, under hot and cold conditions. | 15th Jan 1924 | Box 30 \ 6 Scan151 | |
| Experimental progress report on a 40/50 car's 4-wheel brakes during a road test. | 17th Jan 1924 | Box 30 \ 6 Scan152 | |
| Front brake effectiveness, oil contamination, servo modifications, and chunking in the brake mechanism. | 7th Jan 1924 | Box 30 \ 6 Scan153 | |
| Customer complaints regarding brake noise and analysis of a proposed servo modification. | 17th Jan 1924 | Box 30 \ 6 Scan154 | |
| Tests on brake pressure distribution, servo operation, and the effects of unequal braking. | 17th Jan 1924 | Box 30 \ 6 Scan155 | |
| The effect of front braking on steering for a 40/50 chassis. | 17th Jan 1924 | Box 30 \ 6 Scan156 | |
| Visit to Chapel-en-le-Frith concerning brake friction materials and squeaking linings. | 12th Jul 1923 | Box 30 \ 6 Scan157 | |
| Clutch wear and the friction co-efficient of Ferodo lining. | 17th Jan 1924 | Box 30 \ 6 Scan158 | |
| Continued note on servo lining wear, attributing excessive wear to lack of cooling facilities. | 18th Nov 1924 | Box 30 \ 6 Scan159 | |
| Diagram of an E.A.C. Servo with three graphs showing its mechanical gain performance under varying conditions. | 18th Nov 1924 | Box 30 \ 6 Scan160 | |
| Tests investigating unequal braking, its effect on steering, and the equalization of braking force. | 12th Jul 1923 | Box 30 \ 6 Scan161 | |
| Servo brake testing, comparing the wear on Ferodo and cast iron liners. | 23th Jan 1924 | Box 30 \ 6 Scan162 | |
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