| Description | Date | Identifier | |
| Design of wider brake drums and steel shoes for the Phantom II vehicle. | 24th Dec 1932 | Box 120 \ 1 scan0112 | |
| Experimentally reducing the thickness of cast iron chassis brake drums to reduce axle weights. | 19th Jan 1933 | Box 120 \ 1 scan0113 | |
| Hand brake squeal on 25-HP Chassis Series 'X' with cast iron brake drums. | 23th Jan 1933 | Box 120 \ 1 scan0114 | |
| The fitting of wider front brake drums to car 19-EX. | 8th Feb 1933 | Box 120 \ 1 scan0115 | |
| Potential production of cast iron brake drums and related cost implications. | 16th Feb 1933 | Box 120 \ 1 scan0116 | |
| Standardisation of Lake & Elliott cast iron ribbed brake drums for 25 HP vehicles. | 11th Oct 1932 | Box 120 \ 1 scan0117 | |
| Standardisation form detailing the fitting of a new part to an X series chassis, including test date and costs. | 25th Aug 1931 | Box 120 \ 1 scan0118 | |
| Potential out of balance issues with brake drums on Phantom II & 25 HP chassis. | 22th Jun 1933 | Box 120 \ 1 scan0119 | |
| Millenite brake drum castings and a new process from Messrs. Lake & Elliot Ltd. | 21th Jul 1933 | Box 120 \ 1 scan0120 | |
| Letter from a supplier discussing a price reduction for Millenite brake drum castings. | 18th Jul 1933 | Box 120 \ 1 scan0121 | |
| Chemical composition and mechanical properties of Millenite cast iron bars. | 29th Jul 1933 | Box 120 \ 1 scan0122 | |
| Requesting an order for new Milenite brake drums for testing on Bentley and 40/50 models. | 29th Jul 1933 | Box 120 \ 1 scan0123 | |
| Letter to Messrs. Lake & Elliott regarding the material and production methods for brake drums. | 1st Aug 1933 | Box 120 \ 1 scan0124 | |
| Page 2 of a letter to the Buying Department regarding the importance of maintaining high quality. | 1st Aug 1933 | Box 120 \ 1 scan0125 | |
| The receipt and testing of sample brake drums from an external supplier. | 7th Sep 1933 | Box 120 \ 1 scan0126 | |
| Cost-benefit of a new production method for brake drums. | 8th Sep 1933 | Box 120 \ 1 scan0127 | |
| Loose studs found on Bentley brake drums. | 13th Dec 1933 | Box 120 \ 1 scan0128 | |
| Investigation into an issue with the studs on Bentley Brake Drums. | 18th Dec 1933 | Box 120 \ 1 scan0129 | |
| Failure in the locking device for the Bentley front axle brake drum and proposing a new scheme. | 18th Dec 1933 | Box 120 \ 1 scan0130 | |
| Proposed improvement to Bentley brake drums by substituting bolts for studs. | 2nd Jan 1934 | Box 120 \ 1 scan0131 | |
| Letter from Holden & Hunt regarding their patent brake drum and its exhibition at the Motor Show. | 12th Oct 1934 | Box 120 \ 1 scan0132 | |
| Promotional brochure for Holden & Hunt high tensile steel brake drums and the company's electric resistance welding services. | 12th Oct 1934 | Box 120 \ 1 scan0133 | |
| Specification leaflet for H&H steel brake drums, detailing their construction, material, and performance tests. | 24th Nov 1934 | Box 120 \ 1 scan0134 | |
| Supply and testing of cast iron brake drums from Wycliffe Foundry Co. | 24th Nov 1934 | Box 120 \ 1 scan0135 | |
| The material properties of cast iron brake drums and a recommendation to machine and test samples from Leys Malleable Castings Co. | 21th Dec 1934 | Box 120 \ 1 scan0136 | |
| Internal report on Ferodo tests of Lepaz Morris brake drums. | 1st May 1934 | Box 120 \ 1 scan0137 | |
| Test report on Lepaz brake drums, detailing scoring, distortion, and test procedures. | 1st May 1934 | Box 120 \ 1 scan0138 | |
| Continued report on Lepaz brake drums, detailing distortion, test procedures, and material comparisons. | 1st May 1934 | Box 120 \ 1 scan0139 | |
| Comparison of LEPAZ brake drums with steel and cast iron, including a recommendation for lining material. | 1st May 1934 | Box 120 \ 1 scan0140 | |
| Internal report from the Chief Tester on brake drum tests for Messrs. Ley's of Derby. | 30th Apr 1934 | Box 120 \ 1 scan0141 | |
| The particulars and parameters for a series of tests. | 30th Apr 1934 | Box 120 \ 1 scan0142 | |
| Graph from Ley's Malleable Castings Co., Ltd. detailing the effect of temperature on the tensile properties of 'Lepaz'. | 3rd Apr 1936 | Box 120 \ 1 scan0143 | |
| Criticism of the recommended brake scheme for the Wraith model, specifically the use of aluminium brake drums. | 3rd Apr 1936 | Box 120 \ 1 scan0144 | |
| Modification for the front brake drums on the Wraith II and Phantom III models. | 9th Jul 1936 | Box 120 \ 1 scan0145 | |
| Correcting the subject of a previous memo regarding front brake drums from Phantom III to Wraith II. | 10th Jul 1936 | Box 120 \ 1 scan0146 | |
| Correction memo clarifying that a previous document on front brake drums should refer to the Wraith II model instead of the Phantom III. | 11th Jul 1936 | Box 120 \ 1 scan0147 | |
| Crackling noise in aluminium brake drums on Bentley and Wraith models due to liner roughness. | 1st Oct 1936 | Box 120 \ 1 scan0148 | |
| Secret internal memo discussing quotations for aluminium die-cast brake drums for the Wraith model. | 6th Jan 1937 | Box 120 \ 1 scan0149 | |
| The modification of Wraith brake drums to use fewer driving dogs. | 6th Jan 1937 | Box 120 \ 1 scan0150 | |
| Listing actions required for Bentley aluminium drums due to a stock shortage. | 12th Jan 1937 | Box 120 \ 1 scan0151 | |
| Quotations for different brake drum materials for the Phantom III. | 13th Jan 1937 | Box 120 \ 1 scan0152 | |
| Sourcing and ordering of inexpensive iron brake drums for a Bentley. | 15th Jan 1937 | Box 120 \ 1 scan0153 | |
| Request to send various levers and a set of Bentley Ferodo to the Repair Department for use with aluminium brake drums. | 15th Jan 1937 | Box 120 \ 1 scan0154 | |
| Letter to a supplier discussing quotations and design modifications for casting Phantom III front and rear brake drums. | 15th Jan 1937 | Box 120 \ 1 scan0155 | |
| Letter discussing the economics and production methods for brake drums. | 15th Jan 1937 | Box 120 \ 1 scan0156 | |
| Letter from Ley's Malleable Castings Co. Ltd. regarding the casting of Front and Rear Drums G.84798 and G.84797. | 16th Jan 1937 | Box 120 \ 1 scan0157 | |
| Experimenting with various materials for iron brake drums on Phantom III and Bentley models. | 18th Jan 1937 | Box 120 \ 1 scan0158 | |
| Enquiry to Walker Steel Works Ltd. about the supply and price of 'Walloy' alloy rings for experimental brake drum liners. | 20th Jan 1937 | Box 120 \ 1 scan0159 | |
| Letter from Walker Steel Works, Ltd. acknowledging an enquiry for 'WALLOY' material for relining aluminium brake drums. | 21th Jan 1937 | Box 120 \ 1 scan0160 | |
| Letter from Walker Steel Works regarding their 'Walloy' material for relining Aluminium Brake Drums. | 22th Jan 1937 | Box 120 \ 1 scan0161 | |
| Letter from Walker Steel Works Ltd. in Sheffield to the Experimental Department in Derby, proposing a meeting. | 22th Jan 1937 | Box 120 \ 1 scan0162 | |
| Letter to Ley's Malleable Castings Co. Ltd. enclosing a brake drum drawing for a quotation. | 25th Jan 1937 | Box 120 \ 1 scan0163 | |
| Letter to Walker Steel Works Ltd. regarding experiments with aluminium brake drums and an enquiry about 'Walloy' castings. | 25th Jan 1937 | Box 120 \ 1 scan0164 | |
| Letter from Walker Steel Works Ltd. to the Experimental Department regarding rings for relining aluminium drums. | 26th Jan 1937 | Box 120 \ 1 scan0165 | |
| Letter to The Walker Steel Works, Ltd. regarding a quotation for 'Walloy' brake drum liners and arranging a meeting. | 30th Jan 1937 | Box 120 \ 1 scan0166 | |
| Recurring issue of rear brake drums rubbing on 4¼ Bentley models and a request to alter drawings. | 1st Feb 1937 | Box 120 \ 1 scan0167 | |
| Letter from Walker Steel Works Ltd. arranging a meeting with the Experimental Department. | 1st Feb 1937 | Box 120 \ 1 scan0168 | |
| Letter to Walker Steel Works Ltd. regarding the cost and suitability of iron for liners and drums. | 4th Feb 1937 | Box 120 \ 1 scan0169 | |
| Unsatisfactory performance and high cost of Ley's 'Lepaz' brake drum material. | 12th Feb 1937 | Box 120 \ 1 scan0170 | |
| Outlining the construction of three types of Bentley aluminium front drums for testing contraction crackles. | 13th Feb 1937 | Box 120 \ 1 scan0171 | |
| Letter to a supplier concerning the testing of 'Lepaz' front drums and investigating squeaking troubles. | 18th Feb 1937 | Box 120 \ 1 scan0172 | |
| Letter from Ley's Malleable Castings Co. Ltd. acknowledging a letter regarding 'Lepaz' Drums. | 20th Feb 1937 | Box 120 \ 1 scan0173 | |
| Enquiry for Wraith brake drum liners made of 'Walloy' material. | 20th Jan 1937 | Box 120 \ 1 scan0174 | |
| Directive to trial a front brake damper piston in brass instead of stainless steel to save cost. | 25th Jan 1937 | Box 120 \ 1 scan0175 | |
| To G.W. Hancock in France regarding a Brimol drum and the fitment of new servo cams. | 19th Feb 1937 | Box 120 \ 1 scan0176 | |
| Order for 4 Phantom III front brake drum castings from Ley's. | 2nd Mar 1937 | Box 120 \ 1 scan0177 | |
| Letter to Ley's Malleable Castings Co. Ltd. regarding a quotation and order for four front drum castings. | 2nd Mar 1937 | Box 120 \ 1 scan0178 | |
| Request to manufacture 8 sets of castings for Bentley Aluminium Brake Drums as the current ones are insufficient. | 9th Sep 1937 | Box 120 \ 1 scan0179 | |
| Modification to front aluminium brake drums on a 5-B-IV model to address a crackling noise. | 9th Mar 1937 | Box 120 \ 1 scan0180 | |
| Damage to a vehicle's brake drum and steering levers after a towing incident. | 17th Mar 1937 | Box 120 \ 1 scan0181 | |
| Confirming the despatch of a faulty O.S.F. brake drum to Derby from Chateauroux, France. | 18th Mar 1937 | Box 120 \ 1 scan0182 | |
| Requesting a drawing for a standardised Bentley front brake drum. | 2nd Apr 1937 | Box 120 \ 1 scan0183 | |
| Requesting an update on the introduction of aluminium brake drums for Bentley, attaching a letter from Raymond Mays. | 14th Apr 1937 | Box 120 \ 1 scan0184 | |
| Copy of a letter from Raymond Mays to A.F. Sidgreaves regarding satisfaction with brake modifications. | 13th Apr 1937 | Box 120 \ 1 scan0185 | |
| Brake drums with increased rib area to prevent overheating. | 23th Apr 1937 | Box 120 \ 1 scan0186 | |
| Production assessment for the 'L' Series chassis, noting a nil tool cost. | 18th Aug 1931 | Box 120 \ 1 scan0187 | |
| Casting growth issues in aluminium brake drums and proposed heat treatment tests. | 27th Apr 1937 | Box 120 \ 1 scan0188 | |
| Ongoing development and issues with aluminium brake drums. | 29th Apr 1937 | Box 120 \ 1 scan0189 | |
| Requesting the construction of a new pair of aluminium brake drums to replace a crackling set. | 9th Jun 1937 | Box 120 \ 1 scan0190 | |
| Revised, more convenient heat treatment process for aluminium drums. | 17th Jun 1937 | Box 120 \ 1 scan0191 | |
| Costs and feasibility of casting brake drums in the reorganised iron foundry. | 17th Jun 1937 | Box 120 \ 1 scan0192 | |
| Conversation about potential crackling issues with Bentley aluminium drums. | 21th Jun 1937 | Box 120 \ 1 scan0193 | |
| Requesting the working surface of a brake drum be turned true for use on a test rig. | 25th Jun 1937 | Box 120 \ 1 scan0194 | |
| Complaints of creaking internal brake noise in P.III, 25/30 and Bentley models, with a recommendation to use high pressure grease. | 26th Jun 1937 | Box 120 \ 1 scan0195 | |
| The unacceptable eccentricity of Bentley rear brake drums (G.100981) due to incorrect jig usage during grinding. | 29th Jun 1937 | Box 120 \ 1 scan0196 | |
| Proposing the use of 'Chromidium' for Bentley brake drums as a cost-saving measure against 'Millenite' iron. | 5th Jul 1937 | Box 120 \ 1 scan0197 | |
| The approval and testing of Chromidium brake drums. | 7th Jul 1937 | Box 120 \ 1 scan0198 | |
| Quality and performance of Chromidium brake drums. | 12th Jul 1937 | Box 120 \ 1 scan0199 | |
| Request to test newly cast Phantom III brake drums on experimental cars. | 28th Jul 1937 | Box 120 \ 1 scan0200 | |
| Availability and piece number for Phantom III brake drums. | 3rd Aug 1937 | Box 120 \ 1 scan0201 | |
| Letter to Qualcast Limited regarding the return of drawings for brake drums with cast-in end plates. | 7th Aug 1937 | Box 120 \ 1 scan0202 | |
| Letter to Leys Malleable Castings Ltd. returning defective Lepaz brake drum castings for the Phantom III. | 16th Aug 1937 | Box 120 \ 1 scan0203 | |
| Second set of defective Phantom III front brake drums from Leys Malleable Castings. | 16th Aug 1937 | Box 120 \ 1 scan0204 | |
| Complaint about the eccentricity of Bentley rear brake drums and establishing manufacturing tolerances. | 19th Aug 1937 | Box 120 \ 1 scan0205 | |
| The replacement of aluminium brake drums with new cast iron drums on the Wraith III. | 24th Aug 1937 | Box 120 \ 1 scan0206 | |
| From the Iron Foundry regarding the production and casting of Phantom III brake drums. | 2nd Sep 1937 | Box 120 \ 1 scan0207 | |
| The use of R.R. Brake Drum Cast Iron for all new brake drums sent for testing and standardisation. | 3rd Sep 1937 | Box 120 \ 1 scan0208 | |
| Laboratory examination report on the construction and finish of a Lincoln chassis brake drum. | 3rd Sep 1937 | Box 120 \ 1 scan0209 | |
| Foundry tests and the chemical composition analysis of a cast iron Lincoln drum. | 3rd Sep 1937 | Box 120 \ 1 scan0210 | |
| Laboratory report featuring a photograph of a metal component section. | 9th Sep 1937 | Box 120 \ 1 scan0211 | |
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