| Description | Date | Identifier | |
| The Marles (Patent) Steering Gear, Series 7 & 8. | 14th Mar 1935 | Box 28 \ 3 Scan136 | |
| Request to return loaned 'Gemmer Model 370' steering gear parts to The Adamant Engineering Co. Ltd. | 14th Mar 1935 | Box 28 \ 3 Scan137 | |
| Letter to Adamant Engineering concerning the assembly of a Bentley steering gear and the return of loaned parts. | 14th Mar 1935 | Box 28 \ 3 Scan138 | |
| Letter from Adamant Engineering Company regarding a standard top cover for a gear. | 15th Mar 1935 | Box 28 \ 3 Scan139 | |
| Invoice from Adamant Engineering Co. Ltd. for three sets of Cams and Rollers. | 20th Mar 1935 | Box 28 \ 3 Scan140 | |
| Letter to Adamant Engineering Co. Ltd. confirming a three-week delivery for a 'double tooth follower type' steering component. | 21th Mar 1935 | Box 28 \ 3 Scan141 | |
| Adaptation of the standard 17 Marles steering to suit the 20/25 chassis, including modifications and bearing options. | 22th Feb 1935 | Box 28 \ 3 Scan142 | |
| Letter from Fairey Aviation Company to E.W. Hives regarding a steering stabiliser for adaptation to aircraft controls. | 22th Mar 1935 | Box 28 \ 3 Scan143 | |
| Letter from Adamant Engineering regarding the delivery of a small double-tooth type steering gear and a potential delay due to sourcing parts from the USA. | 23th Mar 1935 | Box 28 \ 3 Scan144 | |
| Mechanical efficiency and weight of the Marles Steering gear for the Spectre model. | 3rd Apr 1935 | Box 28 \ 3 Scan145 | |
| Efficiency and testing of the Marles Steering gear for the Spectre model. | 3rd Apr 1935 | Box 28 \ 3 Scan146 | |
| Method for grinding the Marles steering box worm to standardise it for 20/25, Spectre, and Wraith chassis. | 17th Apr 1935 | Box 28 \ 3 Scan147 | |
| Letter to Adamant Engineering regarding unsatisfactory results with double tooth steering components. | 25th Apr 1935 | Box 28 \ 3 Scan148 | |
| Letter from Adamant Engineering Company arranging a meeting to discuss issues with a Bentley Steering gear. | 27th Apr 1935 | Box 28 \ 3 Scan149 | |
| Letter from Adamant Engineering Company regarding the specifications and dispatch of a double tooth gear for a Bentley car. | 29th Apr 1935 | Box 28 \ 3 Scan150 | |
| Letter to Comdr. Matravers of The Adamant Engineering Co. Ltd. confirming a meeting. | 1st May 1935 | Box 28 \ 3 Scan151 | |
| General arrangement of Marles Steering Gear RH 2 inch type. | 24th Apr 1935 | Box 28 \ 3 Scan152 | |
| General arrangement drawing of a Marles R.H. 1 5/8 type steering gear. | 16th Mar 1934 | Box 28 \ 3 Scan153 | |
| Blueprint for a roller assembly with detailed specifications and dimensions. | 20th Feb 1935 | Box 28 \ 3 Scan154 | |
| General arrangement of a Marles right-hand steering gear, 1 31/32 type. | 12th Feb 1935 | Box 28 \ 3 Scan155 | |
| Sticking points and potential solutions for the Spectre Marles steering system. | 10th May 1935 | Box 28 \ 3 Scan156 | |
| The challenges and methods of grinding a Hindley worm gear. | 10th May 1935 | Box 28 \ 3 Scan157 | |
| Bearing alloy tests, Ford V.8 rear axles, Bentley tappet noise, and steering components. | 10th May 1935 | Box 28 \ 3 Scan158 | |
| Requesting the settlement of a £20 invoice for steering. | 24th May 1935 | Box 28 \ 3 Scan159 | |
| Issues with Marles steering on Spectre models, comparing it to La Salle steering and requesting adjustments and inspection. | 29th May 1935 | Box 28 \ 3 Scan160 | |
| Letter to The Adamant Engineering Co. Ltd. discussing the reasons for tight spots on a large double tooth Marles gear. | 30th May 1935 | Box 28 \ 3 Scan161 | |
| Letter discussing potential manufacturing errors causing tight spots in gear components. | 30th May 1935 | Box 28 \ 3 Scan162 | |
| Requesting the production of left and right-hand rockershafts for a Spectre steering box to be used on the 25 HP model. | 6th Jun 1935 | Box 28 \ 3 Scan163 | |
| Invoice from Adamant Engineering Co. Ltd. for an L7 Gear, seeking approval for payment. | 6th Jun 1935 | Box 28 \ 3 Scan164 | |
| Letter from Adamant Engineering Co., Ltd. regarding invoice 17827 for an 'L7' Type Gear and parts. | 5th Jun 1935 | Box 28 \ 3 Scan165 | |
| Return of loaned steering gear parts to The Adamant Engineering Co. | 8th Jun 1935 | Box 28 \ 3 Scan166 | |
| Requesting the return of loaned 'Marles' L.7 type R.H. Steering Gear parts. | 8th Jun 1935 | Box 28 \ 3 Scan167 | |
| Letter from Adamant Engineering discussing drawings of a Bentley gear cam track and roller to investigate interference causing tight spots. | 3rd Jun 1935 | Box 28 \ 3 Scan168 | |
| Letter from Adamant Engineering Company explaining the complex interaction between a roller and cam track, referencing accompanying drawings. | 3rd Jun 1935 | Box 28 \ 3 Scan169 | |
| Letter to Adamant Engineering Co. Ltd. arranging a meeting to discuss a large gear and the sending of a steering gear. | 17th Jun 1935 | Box 28 \ 3 Scan170 | |
| Request to send the Spectre Steering Box to Adamant Engineering Co. Ltd. in Luton. | 17th Jun 1935 | Box 28 \ 3 Scan171 | |
| Letter from Adamant Engineering Company confirming a meeting with Mr. Hardy. | 18th Jun 1935 | Box 28 \ 3 Scan172 | |
| Request to place an order with Adamant Engineering Co. for special cams for experimental Spectre steering. | 21th Jun 1935 | Box 28 \ 3 Scan173 | |
| Supplier's recommendation to use steel instead of brass for roller bearing cages in a steering system. | 21th Jun 1935 | Box 28 \ 3 Scan174 | |
| Comparison of R.R. Marles steering and La Salle steering, detailing design differences to understand performance variations. | 26th Jun 1935 | Box 28 \ 3 Scan175 | |
| Analysis of mechanical efficiency differences between various steering gear designs, comparing an R.R. gear with a La Salle gear. | 26th Jun 1935 | Box 28 \ 3 Scan176 | |
| Program of experiments on the Spectre gear, focusing on cam design modifications. | 26th Jun 1935 | Box 28 \ 3 Scan177 | |
| Letter to Adamant Engineering Co. Ltd. regarding the delivery of experimental double tooth cams and rollers. | 4th Jul 1935 | Box 28 \ 3 Scan178 | |
| Letter from Adamant Engineering Company regarding fitment issues with steering box components they are manufacturing. | 5th Jul 1935 | Box 28 \ 3 Scan179 | |
| Blueprint of a rocker shaft L7 and L8 type RH. | 24th Jun 1930 | Box 28 \ 3 Scan180 | |
| Blueprint drawing for a serrated pin for a roller. | 21th Jul 1930 | Box 28 \ 3 Scan181 | |
| Requesting the dispatch of a Spectre steering rockershaft to Adamant Engineering Co. for modification. | 6th Aug 1935 | Box 28 \ 3 Scan182 | |
| Letter to Adamant Engineering Co. Ltd. regarding the return of a rockershaft steering box and an inquiry about a cam. | 6th Aug 1935 | Box 28 \ 3 Scan183 | |
| Letter from Adamant Engineering Company regarding the dispatch and return of steering components. | 12th Aug 1935 | Box 28 \ 3 Scan184 | |
| Request for the manufacture of two housings to test cam bearing friction for Marles Steering on Spectre & 25 HP models. | 27th Aug 1935 | Box 28 \ 3 Scan185 | |
| Requesting an urgent order of steering components from the Adamant Engineering Co. for experimental work on a 25 HP car. | 5th Sep 1935 | Box 28 \ 3 Scan186 | |
| Requesting steering adjustments on car 3-B-IV, to remove backlash and reduce spring movement. | 6th Sep 1935 | Box 28 \ 3 Scan187 | |
| Problems with the 'Spectre' steering and proposing a plan to test and develop it in France using car 21-G-IV. | 6th Sep 1935 | Box 28 \ 3 Scan188 | |
| The modifications and trial arrangements for the steering gear of the Spectre and 20/25 HP models. | 6th Sep 1935 | Box 28 \ 3 Scan189 | |
| Specifications for three build variations of 'Gear No. 2' and associated housing modifications. | 6th Sep 1935 | Box 28 \ 3 Scan190 | |
| List of parts to be supplied by Adamant Engineering Co. and Timkens for two different gear assemblies. | 6th Sep 1935 | Box 28 \ 3 Scan191 | |
| List of parts on order for Gear No. 2 from Adamants and Timkens. | 6th Sep 1935 | Box 28 \ 3 Scan192 | |
| Letter from Adamant Engineering Company regarding a revised delivery schedule for special tools and gauges. | 10th Sep 1935 | Box 28 \ 3 Scan193 | |
| Postscript to a letter clarifying a mistake regarding instructions for rollers and lead cams. | 10th Sep 1935 | Box 28 \ 3 Scan194 | |
| Letter to Adamant Engineering Co. Ltd. regarding a delay in the completion of steering parts. | 13th Sep 1935 | Box 28 \ 3 Scan195 | |
| Letter from a supplier regarding production difficulties and a revised delivery schedule for special Cams and Rollers. | 14th Sep 1935 | Box 28 \ 3 Scan196 | |
| Second page of a letter to W.A. Robotham regarding the urgency of right-hand cams. | 14th Sep 1935 | Box 28 \ 3 Scan197 | |
| Letter to The Adamant Engineering Co.Ltd. clarifying an order for cams and rollers. | 17th Sep 1935 | Box 28 \ 3 Scan198 | |
| Letter from a supplier acknowledging an urgent order for special Cams and Rollers. | 18th Sep 1935 | Box 28 \ 3 Scan199 | |
| Letter from Adamant Engineering Company regarding the delivery of Cams, Rollers, a drawing number correction, and Timken Bearings. | 19th Sep 1935 | Box 28 \ 3 Scan200 | |
| Letter from Adamant Engineering Company Limited clarifying their position on supplying Cups for Timken Bearings. | 19th Sep 1935 | Box 28 \ 3 Scan201 | |
| Specification sheet for rollers used in Spectre & 20/25 HP steering parts. | 27th Sep 1935 | Box 28 \ 3 Scan202 | |
| Specification table for Cams used in Spectre & 20/25 HP Steering Parts. | 27th Sep 1935 | Box 28 \ 3 Scan203 | |
| Letter from Adamant Engineering Company regarding a proposed meeting at Olympia to settle matters concerning experimental sets. | 18th Oct 1935 | Box 28 \ 3 Scan204 | |
| Letter to Commander Matravers arranging to meet at the Rolls-Royce stand at Olympia. | 21th Oct 1935 | Box 28 \ 3 Scan205 | |
| Letter from Adamant Engineering Company to W.A. Robotham regarding a missed meeting and arranging a visit. | 24th Oct 1935 | Box 28 \ 3 Scan206 | |
| Letter from Adamant Engineering Company to Mr. Robotham arranging a meeting and lunch at Olympia. | 22th Oct 1935 | Box 28 \ 3 Scan207 | |
| Letter to Commander Matravers of Adamant Engineering arranging a meeting to discuss steering matters. | 29th Oct 1935 | Box 28 \ 3 Scan208 | |
| Letter from Adamant Engineering Co. to W.A. Robotham confirming a visit to Derby. | 31th Oct 1935 | Box 28 \ 3 Scan209 | |
| Specification for the Marles Gear, including a list of supplied parts. | 5th Nov 1935 | Box 28 \ 3 Scan210 | |
| Corrections to Phantom III steering components by the Adamant Co. | 7th Nov 1935 | Box 28 \ 3 Scan211 | |
| Oil leak from the Ph.III & 25 HP Marles Type Steering gear and a suggested modification. | 11th Nov 1935 | Box 28 \ 3 Scan212 | |
| Oil leak from a Ph.III & 25 HP Marles Type Steering box, identifying the cause and proposing a modification. | 11th Nov 1935 | Box 28 \ 3 Scan213 | |
| Letter from Adamant Engineering Company confirming an alteration to an order for Cams and Rollers. | 11th Dec 1935 | Box 28 \ 3 Scan214 | |
| Modifications to the Marles Steering box for the Phantom III model. | 17th Dec 1935 | Box 28 \ 3 Scan215 | |
| Comparison of torsional deflection and stiffness for various rocker shaft designs under a specific load. | 13th Dec 1935 | Box 28 \ 3 Scan216 | |
| The weakness of a Marles steering box and recommendations for strengthening it with larger bolts. | 20th Dec 1935 | Box 28 \ 3 Scan217 | |
| Letter from Dunlop Pneumatic Tyre Co. Ltd. discussing tyre balance guarantees and valve fitting specifications. | 2nd Dec 1911 | Box 28 \ 4 Scan001 | |
| The second page of a letter from The Dunlop Pneumatic Tyre Co Ltd to Wm. Cowen Esq. | 2nd Dec 1911 | Box 28 \ 4 Scan002 | |
| Departmental memo forwarding a letter from the Dunlop Tyre Co. for comment. | 4th Dec 1911 | Box 28 \ 4 Scan003 | |
| Meeting notes concerning steering wobbles and a scheduled discussion with the Michelin Tyre Co. about tyre balance. | 4th Dec 1911 | Box 28 \ 4 Scan004 | |
| Committee response to suggestions for improving lubrication access for the steering rod and gearbox filler. | 4th Dec 1911 | Box 28 \ 4 Scan005 | |
| Committee response regarding a suggestion to use an overflow cock instead of a dipstick for indicating gearbox oil level. | 14th Oct 1913 | Box 28 \ 4 Scan006 | |
| Committee meeting minute discussing a suggestion by Mr. Henning for lubricating the steering rod. | 4th Dec 1911 | Box 28 \ 4 Scan007 | |
| Meeting minutes discussing steering lubrication methods and a locking scheme for a specific car. | 6th Dec 1911 | Box 28 \ 4 Scan008 | |
| Departmental memo discussing tyre balance issues and applying pressure on manufacturers. | 6th Dec 1911 | Box 28 \ 4 Scan009 | |
| Inadvisable strategy of threatening a supplier by considering buying tyres from other manufacturers. | 7th Oct 1911 | Box 28 \ 4 Scan010 | |
| Letter discussing the superiority of British Oak over Hickory for wheel spokes. | 5th Dec 1911 | Box 28 \ 4 Scan011 | |
| Letter from Dunlop explaining the use of British Oak over American Hickory for wheel spokes. | 7th Dec 1911 | Box 28 \ 4 Scan012 | |
| Meeting minutes regarding a suggestion for the lubrication of the steering rod joint. | 3rd Jan 1912 | Box 28 \ 4 Scan013 | |
| Meeting minutes discussing the issue of steering wobbles and the need for further tyre balance testing. | 3rd Jan 1912 | Box 28 \ 4 Scan014 | |
| Steering wobble and tyre balance tests. | 11th Jan 1912 | Box 28 \ 4 Scan015 | |
| Departmental memo discussing the issue of steering wobbles caused by unbalanced tyres and the unsatisfactory method of fixing balance weights. | 14th Jun 1912 | Box 28 \ 4 Scan016 | |
| Departmental memo discussing potential solutions for issues caused by unbalanced tyres. | 18th Mar 1912 | Box 28 \ 4 Scan017 | |
| Fixing security bolts to prevent steering wobbles caused by unbalanced front wheels. | 18th Mar 1912 | Box 28 \ 4 Scan018 | |
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