| Description | Date | Identifier | |
| Letter to B. Hopkins regarding the price and production of graphite bronze material for brakes and clutches. | 18th Nov 1937 | Box 129 \ 4 scan0073 | |
| Cost breakdown memo for Cleveland Graphite Bronze facings. | 18th Nov 1937 | Box 129 \ 4 scan0074 | |
| Communication regarding experimental bronze clutch liners from Vandervell Steelbak, London. | 19th Nov 1937 | Box 129 \ 4 scan0075 | |
| Letter to Messrs. Borg & Beck Co.Ltd. clarifying the number of plates being repaired and the associated cost. | 19th Nov 1937 | Box 129 \ 4 scan0076 | |
| Letter from Borg & Beck regarding difficulty balancing 10.A3 clutch covers and requesting permission to weld balancing strips. | 22th Nov 1937 | Box 129 \ 4 scan0077 | |
| Drawing of a special 10 A3 cover, detailing modifications and manufacturing specifications. | 21th Sep 1936 | Box 129 \ 4 scan0078 | |
| Letter from Vandervell Products Ltd. regarding new Clevite clutch facing material and a request to loan a Dynamo and Control Box. | 2nd Nov 1937 | Box 129 \ 4 scan0079 | |
| Letter to Borg & Beck Co. Ltd. inquiring about the development and fitting of new thrust springs for clutches. | 23th Nov 1937 | Box 129 \ 4 scan0080 | |
| Letter to Messrs. Borg & Beck Co. Ltd. agreeing to the welding of a balance strip on a clutch cover flange. | 23th Nov 1937 | Box 129 \ 4 scan0081 | |
| Confirming the fitting of Graphite Bronze Clutch Facings to three specific cars. | 23th Nov 1937 | Box 129 \ 4 scan0082 | |
| Private memo regarding the fitting and performance of graphite bronze clutch facings on a 3½-litre chassis. | 23th Nov 1937 | Box 129 \ 4 scan0083 | |
| Letter from The Cleveland Graphite Bronze Co. discussing an error with incorrectly drilled clutch facings and a new experimental design. | 24th Nov 1937 | Box 129 \ 4 scan0084 | |
| Letter from The Cleveland Graphite Bronze Company regarding developments and testing of clutch plates and facings. | 24th Nov 1937 | Box 129 \ 4 scan0085 | |
| Blueprint of a clutch assembly with a detailed parts list legend. | 20th Oct 1937 | Box 129 \ 4 scan0086 | |
| The supply and performance of Graphite Bronze Clutch Facings. | 24th Nov 1937 | Box 129 \ 4 scan0087 | |
| Letter from clutch manufacturer Borg & Beck confirming a change from Brown Springs to Black Springs. | 25th Nov 1937 | Box 129 \ 4 scan0088 | |
| Letter to Borg & Beck Ltd. requesting prices for various clutch plates and springs. | 1st Dec 1937 | Box 129 \ 4 scan0089 | |
| Letter from Borg & Beck regarding a price request for modified 11' driven plates with Thermoid facings. | 2nd Dec 1937 | Box 129 \ 4 scan0090 | |
| Letter from Borg & Beck Company Ltd concerning the dispatch and rectification of 10' clutch driven plates with Thermoid Facings. | 4th Dec 1937 | Box 129 \ 4 scan0091 | |
| Request to prepare two rings with specific dimensions for testing the 20/25 and 3 1/2 litre clutch. | 6th Dec 1937 | Box 129 \ 4 scan0092 | |
| Letter to Ferodo Ltd. requesting a quote for heat-insulating discs for clutch thrust springs. | 6th Dec 1937 | Box 129 \ 4 scan0093 | |
| Letter from Borg & Beck Company Ltd. providing a service list of prices for clutch parts. | 7th Dec 1937 | Box 129 \ 4 scan0094 | |
| Letter from Ferodo Limited regarding clutch spring insulating pads, comparing punched vs. turned manufacturing methods. | 8th Dec 1937 | Box 129 \ 4 scan0095 | |
| Letter to Messrs Borg & Beck Ltd. regarding an enquiry for a 10' clutch with Thermoid facings for a Bentley. | 10th Dec 1937 | Box 129 \ 4 scan0096 | |
| Letter to Borg & Beck Co. Ltd. about experimentally re-drilling a 10' Cross Cushioned Plate. | 13th Dec 1937 | Box 129 \ 4 scan0097 | |
| Despatch of Ferodo Facings for a 4 1/2 Litre Bentley clutch. | 13th Dec 1937 | Box 129 \ 4 scan0098 | |
| Request for additional sets of Graphite Bronze Facings for a 20/25-HP Clutch. | 13th Dec 1937 | Box 129 \ 4 scan0099 | |
| The testing methodology for Graphite Bronze clutch facings on a 20/25 & 3 1/2 litre Bentley. | 13th Dec 1937 | Box 129 \ 4 scan0100 | |
| Clutch reliability tests, comparing wear and performance of different facing materials. | 13th Dec 1937 | Box 129 \ 4 scan0101 | |
| Clutch spring modifications and performance testing with Ferodo discs. | 13th Dec 1937 | Box 129 \ 4 scan0102 | |
| Test report conclusion recommending the use of Graphite Bronze clutch facings on Bentley models. | 13th Dec 1937 | Box 129 \ 4 scan0103 | |
| Graph comparing the wear characteristics of 'Graphite Bronze' and 'Ferodo Rad 11' driving faces. | 10th Dec 1937 | Box 129 \ 4 scan0104 | |
| Confirming the fitting of a graphite bronze clutch plate to chassis GXK-80. | 14th Dec 1937 | Box 129 \ 4 scan0105 | |
| Letter from Borg & Beck Company regarding a 10-inch clutch for a Bentley application. | 13th Dec 1937 | Box 129 \ 4 scan0106 | |
| The stock availability of Graphite Bronze clutch facings for the 20/25 HP model. | 15th Dec 1937 | Box 129 \ 4 scan0107 | |
| Letter from Borg & Beck regarding issues with the drilling and supply of a 10' Cross Cushion Driven Plate. | 15th Dec 1937 | Box 129 \ 4 scan0108 | |
| Performance of Borg & Beck clutches compared to Long clutch plates on a Bentley. | 20th Dec 1937 | Box 129 \ 4 scan0109 | |
| Letter to Borg & Beck Co. Ltd. acknowledging receipt of a Phantom III clutch plate for trial. | 22th Dec 1937 | Box 129 \ 4 scan0110 | |
| Chasing a promised batch of 20/25-HP Bronze Clutch Facings. | 22th Dec 1937 | Box 129 \ 4 scan0111 | |
| The fitting of a Graphite Bronze Clutch Facing to chassis GBK-14. | 22th Dec 1937 | Box 129 \ 4 scan0112 | |
| Letter to Messrs. Borg & Beck Ltd. requesting cushioning data for a Phantom III clutch plate. | 23th Dec 1937 | Box 129 \ 4 scan0113 | |
| Follow-up letter regarding an unfulfilled order for springs and cancelling an order for clutch plates. | 30th Dec 1937 | Box 129 \ 4 scan0114 | |
| Invoice from Ferodo Ltd for five Ferodo Discs and seeking payment approval. | 30th Dec 1937 | Box 129 \ 4 scan0115 | |
| Invoice from Ferodo Ltd for experimental discs and a request for a covering order. | 31th Dec 1937 | Box 129 \ 4 scan0116 | |
| Price list for Borg & Beck clutches and plates for various car models. | 1st Jan 1938 | Box 129 \ 4 scan0117 | |
| Modifications to a rig for testing Borg & Beck clutch springs. | 1st Jan 1938 | Box 129 \ 4 scan0118 | |
| Covering order for thrust springs from Borg & Beck Ltd. | 7th Jan 1938 | Box 129 \ 4 scan0119 | |
| Letter from The Cleveland Graphite Bronze Co. discussing the development of brake linings and clutch facings. | 7th Jan 1938 | Box 129 \ 4 scan0120 | |
| From The Cleveland Graphite Bronze Co. discussing the feasibility of manufacturing brake servo linings from powdered metal. | 5th Jan 1938 | Box 129 \ 4 scan0121 | |
| Technical memorandum regarding clutch slip and testing methods. | 8th Jan 1938 | Box 129 \ 4 scan0122 | |
| Clutch performance, slipping, and experimental testing methods for smooth pick-up. | 8th Jan 1938 | Box 129 \ 4 scan0123 | |
| Note on how to handle a complaint of slipping under abnormal driving conditions during an experimental test. | 8th Jan 1938 | Box 129 \ 4 scan0124 | |
| List of clutches fitted to various chassis units in January 1938. | 1st Jan 1938 | Box 129 \ 4 scan0125 | |
| Letter from Vandervell Products Ltd. explaining a delivery delay due to scrapped clutch plates. | 8th Jan 1938 | Box 129 \ 4 scan0126 | |
| Experimental Ferodo clutch facings, confirming receipt of parts and amending a previous order. | 12th Jan 1938 | Box 129 \ 4 scan0127 | |
| Blueprint of a 10.5 inch clutch designed for approximately 200 to 220 lbs/feet torque. | 17th Jan 1938 | Box 129 \ 4 scan0128 | |
| Design proposal for a new type of clutch detailing its six main advantages. | 18th Jan 1938 | Box 129 \ 4 scan0129 | |
| Patentability of a pressure plate mounting and resilient finger levers. | 18th Jan 1938 | Box 129 \ 4 scan0130 | |
| Company policy and issues surrounding clutch changeovers for various car models, including the Phantom III and 25/30. | 19th Jan 1938 | Box 129 \ 4 scan0131 | |
| Policy on changing clutch plates for Phantom III and 25/30 HP models in response to chauffeur complaints. | 24th Jan 1938 | Box 129 \ 4 scan0132 | |
| The 25/30 and Bentley clutch failing to stop, caused by excessive run-out on the clutch plate due to strain during gearbox installation. | 27th Jan 1938 | Box 129 \ 4 scan0133 | |
| Letter to Ferodo Ltd. requesting samples of a clutch disc for bursting strength testing and comparison with other materials. | 28th Jan 1938 | Box 129 \ 4 scan0134 | |
| Letter from Ferodo Limited regarding the testing and manufacturing of clutch disc samples. | 29th Jan 1938 | Box 129 \ 4 scan0135 | |
| Letter to the Cleveland Graphite Bronze Company regarding an aluminium tin alloy, servo lining, and clutch facings. | 1st Feb 1938 | Box 129 \ 4 scan0136 | |
| Technical note detailing the properties of graphite bronze for a servo. | 1st Feb 1938 | Box 129 \ 4 scan0137 | |
| Letter from Ferodo Limited confirming the dispatch of material samples S.7732 for testing. | 11th Feb 1938 | Box 129 \ 4 scan0138 | |
| Letter to Ferodo Ltd. concerning the receipt and planned testing of S.7732 facings on a Phantom III car. | 14th Feb 1938 | Box 129 \ 4 scan0139 | |
| Letter from Cleveland Graphite Bronze Co. discussing servo lining, new bearing material, and Clevite clutch facings. | 16th Feb 1938 | Box 129 \ 4 scan0140 | |
| Inquiry regarding the wear patterns on Borg & Beck clutches. | 16th Feb 1938 | Box 129 \ 4 scan0141 | |
| New clutch spring test rig for 10' & 11' Borg & Beck clutches and the findings from its use. | 16th Feb 1938 | Box 129 \ 4 scan0142 | |
| Recommendation to build a new testing rig for clutches with a modification to the stud pitch circle diameter. | 16th Feb 1938 | Box 129 \ 4 scan0143 | |
| Clutch jagger issue with graphite bronze clutch faces on a 3 1/2-litre Bentley chassis. | 17th Feb 1938 | Box 129 \ 4 scan0144 | |
| Customer complaints and wear issues related to Borg & Beck clutches. | 18th Feb 1938 | Box 129 \ 4 scan0145 | |
| Examining clutch friction plates for judder and a proposal to increase clearance to extend clutch life. | 21th Feb 1938 | Box 129 \ 4 scan0146 | |
| Resolving clutch chattering in 25/30 HP & Bentley clutches by fitting a new bronze bush bearing. | 21th Feb 1938 | Box 129 \ 4 scan0147 | |
| Letter to Borg & Beck Co. Ltd. requesting particulars, a drawing, and a curve for a Long clutch with centrifugal assistance for Phantom III cars. | 23th Feb 1938 | Box 129 \ 4 scan0148 | |
| Supply of a clutch spring test rig to a supplier to standardize testing procedures. | 23th Feb 1938 | Box 129 \ 4 scan0149 | |
| Clutch spring test rig and an attached letter to Borg & Beck Ltd. | 25th Feb 1938 | Box 129 \ 4 scan0150 | |
| Letter to Borg & Beck Ltd. regarding a rig for measuring clutch thrust and the results of initial tests. | 25th Feb 1938 | Box 129 \ 4 scan0151 | |
| Page 2 of a letter to Messrs. Borg & Beck Ltd. about a rig for measuring thrust on a pressure plate. | 25th Feb 1938 | Box 129 \ 4 scan0152 | |
| Letter from Borg & Beck Company Ltd. regarding a rig to measure thrust spring pressure on clutches. | 26th Feb 1938 | Box 129 \ 4 scan0153 | |
| Letter from clutch manufacturer Borg & Beck regarding the application of a 12.CB. clutch to the Phantom III. | 28th Feb 1938 | Box 129 \ 4 scan0154 | |
| Letter to Ben Hopkins of Cleveland Graphite Bronze Co. regarding clutch construction, friction materials, and an aluminium tin alloy. | 28th Feb 1938 | Box 129 \ 4 scan0155 | |
| Letter to The United Steel Products Co. requesting particulars of Cor-ten steel. | 1st Mar 1938 | Box 129 \ 4 scan0156 | |
| Quote for a test rig for Borg & Beck clutches. | 2nd Mar 1938 | Box 129 \ 4 scan0157 | |
| Slack in a bronze bush for 20/25 HP and Bentley clutches and the owner's satisfaction after replacement. | 3rd Mar 1938 | Box 129 \ 4 scan0158 | |
| Requesting bench space for a newly completed rig for testing Borg & Beck clutches. | 5th Mar 1938 | Box 129 \ 4 scan0159 | |
| Letter from Borg & Beck Company Ltd. concerning the trial supply of a 10' Semi-Centrifugal Clutch. | 7th Mar 1938 | Box 129 \ 4 scan0160 | |
| Composition, properties, and suitability of Corten steel. | 7th Mar 1938 | Box 129 \ 4 scan0161 | |
| Supply and cost of a test rig for Borg & Beck clutches. | 7th Mar 1938 | Box 129 \ 4 scan0162 | |
| Letter to Borg & Beck Ltd. offering a reduced price for a clutch thrust poundage testing rig. | 8th Mar 1938 | Box 129 \ 4 scan0163 | |
| Letter to Borg & Beck Ltd. concerning the trial and specifications of a 10-inch Semi-Centrifugal Clutch. | 8th Mar 1938 | Box 129 \ 4 scan0164 | |
| Request for a performance curve and price quotation for a centrifugal assistance clutch. | 9th Mar 1938 | Box 129 \ 4 scan0165 | |
| Letter from clutch manufacturer Borg & Beck declining an offer for a test rig. | 9th Mar 1938 | Box 129 \ 4 scan0166 | |
| Refusal of Borg & Beck to purchase a clutch test rig. | 10th Mar 1938 | Box 129 \ 4 scan0167 | |
| Letter from clutch manufacturer Borg & Beck regarding the supply and specification of a 10.C.F. clutch. | 10th Mar 1938 | Box 129 \ 4 scan0168 | |
| Continuation of a letter from Borg & Beck Company Limited regarding a cover assembly from America. | 10th Mar 1938 | Box 129 \ 4 scan0169 | |
| Tensometer test results for a Borg & Beck cast iron clutch plate. | 11th Mar 1938 | Box 129 \ 4 scan0170 | |
| Letter to supplier Borg & Beck concerning the failure of a clutch pressure plate and subsequent material test results. | 15th Mar 1938 | Box 129 \ 4 scan0171 | |
| Instructing the return of a broken 11' pressure plate to Borg & Beck. | 15th Mar 1938 | Box 129 \ 4 scan0172 | |
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