| Description | Date | Identifier | |
| Standardisation sheet for fitting 1500 lbs springs with an old type heavy front axle and 720 worm. | 22th Dec 1926 | Box 68 \ 1 scan0190 | |
| Standardisation of weaker springs in the side steering tube to reduce steering shocks. | 26th Nov 1926 | Box 68 \ 1 scan0191 | |
| Standardization of side steering tube springs for 20 HP and 40/50 Phantom models. | 26th Jan 1927 | Box 68 \ 1 scan0192 | |
| Comparison of steering arrangements with plans for future testing of a new scheme. | 26th Jan 1927 | Box 68 \ 1 scan0193 | |
| Breaking side steering tube springs for the 40/50 HP model, recommending replacement. | 1st Feb 1927 | Box 68 \ 1 scan0194 | |
| Design release and implementation of a side steering tube for changeover work. | 21th Feb 1927 | Box 68 \ 1 scan0195 | |
| Calculations concerning fluid delivery rates and head pressures. | 22th Feb 1927 | Box 68 \ 1 scan0196 | |
| Testing and potential modifications for the 40/50 Side Steering Tube. | 22th Feb 1927 | Box 68 \ 1 scan0197 | |
| Specifications and clearances for side steering tube N.sch.2253. | 25th Feb 1927 | Box 68 \ 1 scan0198 | |
| Testing recommendations for Trials cars, steering issues with chassis 107-TC, and a proposed spring fitting experiment. | 2nd Mar 1927 | Box 68 \ 1 scan0199 | |
| Test results and future plans for side steering tube springs. | 1st Mar 1927 | Box 68 \ 1 scan0200 | |
| Clarifying the use of different springs for various car series in relation to side steering tubes. | 14th Mar 1927 | Box 68 \ 1 scan0201 | |
| Instruction to experimentally assemble a new spring for the Side Steering Tube on a Phantom chassis. | 14th Mar 1927 | Box 68 \ 1 scan0202 | |
| Supplying and testing new springs for the side steering tube. | 14th Mar 1927 | Box 68 \ 1 scan0203 | |
| The fitting of a steering tube, an improved lubrication scheme, and a front axle control. | 14th Mar 1927 | Box 68 \ 1 scan0204 | |
| Standardisation of the side steering tube end to improve the steering. | 9th Feb 1927 | Box 68 \ 1 scan0205 | |
| Fitting of an E2 series chassis, including the test date and associated costs. | 14th Jul 1927 | Box 68 \ 1 scan0206 | |
| Factory cost for supplying and fitting a modified side steering tube. | 12th Mar 1927 | Box 68 \ 1 scan0207 | |
| Issue of blueprints for Side Steering Tubes for the Phantom Chassis. | 21th Mar 1927 | Box 68 \ 1 scan0208 | |
| Blueprint for the Side Steering Tube on the Phantom Chassis, in accordance with scheme 2258. | 29th Mar 1927 | Box 68 \ 1 scan0209 | |
| Arrangement F.76788 for the Side Steering Tube (SEC:7070) on the Phantom Chassis. | 2nd Apr 1927 | Box 68 \ 1 scan0210 | |
| Need for stronger springs for hydraulic shock dampers and side steering tubes. | 25th Apr 1927 | Box 68 \ 1 scan0211 | |
| List of blueprints for guides, springs and ball pads for the Phantom Chassis side steering tube. | 2nd May 1927 | Box 68 \ 1 scan0212 | |
| Instruction regarding a blue print for the Cover for Side Steering Tube Joint on a Phantom Chassis. | 12th May 1927 | Box 68 \ 1 scan0213 | |
| The side steering tube for a Phantom chassis, for use with a spring damped pendulum lever. | 27th May 1927 | Box 68 \ 1 scan0214 | |
| Side steering tube knock, confirming a successful fix on one car and reporting parts incompatibility on two other cars. | 26th Oct 1927 | Box 68 \ 1 scan0215 | |
| Request to obtain springs with a 2000 lbs. rating for a Sports car. | 5th Nov 1927 | Box 68 \ 1 scan0216 | |
| Manufacturing limits for the 40/50 side steering tube and proposing a solution for tolerance issues with internal springs. | 9th Nov 1927 | Box 68 \ 1 scan0217 | |
| Experimental test results for SS Tube Joints, schemes N.Sch 2258 and N.Sch 2301, showing load vs. movement graphs. | 8th Nov 1927 | Box 68 \ 1 scan0218 | |
| Continuation page for 'SCHEME C' detailing spring rating, length, washer thickness, and modification suggestions for part F.76268. | 11th Nov 1927 | Box 68 \ 1 scan0219 | |
| Part changes for the Side Steering Tube on the E.A.C.14 and Phantom Chassis. | 11th Nov 1927 | Box 68 \ 1 scan0220 | |
| Suggesting a change in spring rating for side steering tubes to reduce the number of different parts. | 11th Nov 1927 | Box 68 \ 1 scan0221 | |
| Modifications to the 40/50 HP chassis side steering tube to improve clearances and avoid fouls. | 5th Dec 1927 | Box 68 \ 1 scan0222 | |
| Alterations to a 40/50 S.S. tube and step-irons to clear the axle. | 16th Dec 1927 | Box 68 \ 1 scan0223 | |
| The fitment and approval of a bent side steering tube on a car being used in the south of France. | 20th Dec 1927 | Box 68 \ 1 scan0224 | |
| Fitment of a side steering tube on an experimental car. | 20th Dec 1927 | Box 68 \ 1 scan0225 | |
| The unattractive design of a side steering tube and the plan to send a drawing. | 21th Dec 1927 | Box 68 \ 1 scan0226 | |
| Notification forwarding one print of the improved F.78230 Side Steering Tube for the Phantom Chassis. | 31th Dec 1927 | Box 68 \ 1 scan0227 | |
| Investigation into a failed side steering tube spring. | 28th Dec 1927 | Box 68 \ 1 scan0228 | |
| Micro-examination report on the fractures and material composition of a side steering tube spring. | 31th Dec 1927 | Box 68 \ 1 scan0229 | |
| Query regarding the number of chassis to be fitted with the Phantom side steering tube. | 17th Jan 1928 | Box 68 \ 1 scan0230 | |
| Request to manufacture a tube for GWH's car, referencing a previous instruction. | 27th Jan 1928 | Box 68 \ 1 scan0231 | |
| Modifications to the Phantom steering system, specifically a shortened pendulum lever and a side steering tube. | 14th Feb 1928 | Box 68 \ 1 scan0232 | |
| Implementation of a standardization scheme for the side steering tube. | 14th Feb 1927 | Box 68 \ 1 scan0233 | |
| Experiments and conclusions on side steering tube springs to prevent high-speed wobbles. | 27th Apr 1928 | Box 68 \ 1 scan0234 | |
| Compilation of a summary for 40/50 side steering tubes. | 5th May 1928 | Box 68 \ 1 scan0235 | |
| Specifications table for Phantom side steering tube ends, detailing part numbers, stress ratings, movement, and chassis fitment. | 14th May 1928 | Box 68 \ 1 scan0236 | |
| Order for two types of springs with detailed specifications. | 28th Jun 1928 | Box 68 \ 1 scan0237 | |
| The despatch of three different sets of springs for chassis 29-CL. | 16th Jul 1928 | Box 68 \ 1 scan0238 | |
| Despatch of hydraulic dampers and three sets of experimental side steering tube springs. | 16th Jul 1928 | Box 68 \ 1 scan0239 | |
| Effects of wheel offset, spring rates, and shock absorbers on steering characteristics. | 24th Jul 1928 | Box 68 \ 1 scan0240 | |
| Technical note on shock absorber loads and spring movement to improve ride quality. | 3rd Oct 1928 | Box 68 \ 1 scan0241 | |
| Steering on Chassis No. 66-YC and the effect of special tube springs. | 3rd Oct 1928 | Box 68 \ 1 scan0242 | |
| Testing car 66-YC for steering sponginess and high-speed wobble, with details of modifications made. | 6th Oct 1928 | Box 68 \ 1 scan0243 | |
| Experimental springs for chassis N.122 KR, advising against their use due to potential issues. | 1st May 1939 | Box 68 \ 1 scan0244 | |
| Issuing tracings for special side steering tube springs and ball pads for the Phantom Chassis 122-KR. | 10th May 1929 | Box 68 \ 1 scan0245 | |
| Redesign of petrol tank fittings and the switch to a vacuum feed system for cars with 4-wheel brakes. | 27th Jun 1924 | Box 68 \ 1 scan0246 | |
| Secret memorandum discussing modifications to the luggage grid, petrol tank, and chassis for various models. | 7th Aug 1924 | Box 68 \ 1 scan0247 | |
| Design changes for the 'V' series petrol tanks, including a partition and new filters. | 28th Nov 1924 | Box 68 \ 1 scan0248 | |
| Cancelling a special oil pump and replacing it with a relief valve box system for engine lubrication. | 1st Dec 1924 | Box 68 \ 1 scan0249 | |
| Confirming instructions to use the 'U' Series petrol tank for the 'V' Series, and a new tank for the 'W' Series. | 11th Dec 1924 | Box 68 \ 1 scan0250 | |
| Approval and fitting of a new two-level device and double filter for the 'V' Series petrol tank. | 9th Dec 1924 | Box 68 \ 1 scan0251 | |
| The petrol tank for the 'V' series. | 15th Dec 1924 | Box 68 \ 1 scan0252 | |
| Confirming Mr. Royce's decision not to use the double level device on the 'V' Series, making its petrol tank identical to the 'U' Series. | 9th Dec 1924 | Box 68 \ 1 scan0253 | |
| Design alterations to the petrol tank, its filters, and sump. | 11th Jun 1925 | Box 68 \ 1 scan0254 | |
| The availability of a petrol tank with a reserve compartment for the 7-EX 'V' series car. | 23th Jun 1925 | Box 68 \ 1 scan0255 | |
| Improvements and new features for the new Phantom chassis. | 1st Jul 1925 | Box 68 \ 1 scan0256 | |
| Functionality and dial readings of a two-level petrol tank device. | 13th Jul 1925 | Box 68 \ 1 scan0257 | |
| Faults with the petrol tank and vent system for the New Phantom model. | 20th Aug 1925 | Box 68 \ 1 scan0258 | |
| Necessity of petrol filters and specifications for future fuel tanks. | 20th Aug 1925 | Box 68 \ 1 scan0259 | |
| Fuel filter gauze specifications, materials, and performance in carburettors. | 9th Sep 1925 | Box 68 \ 1 scan0260 | |
| Modifications to the New Phantom petrol tank. | 9th Sep 1925 | Box 68 \ 1 scan0261 | |
| Petrol tank design, pump capacities, and the inclusion of an ingoing filter or strainer. | 10th Sep 1925 | Box 68 \ 1 scan0262 | |
| The decision to abandon the separate compartment petrol tank design in favour of a two-suction pipe system. | 29th Sep 1925 | Box 68 \ 1 scan0263 | |
| Modifications to the Phantom petrol tank, specifically abandoning the weir for a more accurate level gauge. | 1st Oct 1925 | Box 68 \ 1 scan0264 | |
| Design alterations to the Phantom petrol tank, including a new side filler and changes to the central suspension. | 3rd Oct 1925 | Box 68 \ 1 scan0265 | |
| Suggestions for reducing petrol loss from an air lock in the petrol tank and modifying the cap's spring lock. | 5th Dec 1925 | Box 68 \ 1 scan0266 | |
| Supplementary petrol tank lever markings and the design of the petrol gauge for the new Phantom model. | 17th Dec 1925 | Box 68 \ 1 scan0267 | |
| The new petrol tank for the Phantom model, detailing changes to the reserve supply marking and petrol gauge. | 19th Dec 1925 | Box 68 \ 1 scan0268 | |
| Design improvements for petrol tanks, with sketches. | 8th Feb 1926 | Box 68 \ 1 scan0269 | |
| Improvements and early standardisation for the rear petrol tank, carrier and guard. | 27th Feb 1926 | Box 68 \ 1 scan0270 | |
| Design improvements for petrol fillers and petrol gauges. | 15th Feb 1926 | Box 68 \ 1 scan0271 | |
| New louvered bonnet and a petrol tank alteration for a 20 HP car. | 19th Mar 1926 | Box 68 \ 1 scan0272 | |
| Requesting an inspection of a modified petrol tank for the New Phantom. | 20th May 1926 | Box 68 \ 1 scan0273 | |
| Standardisation of a petrol tank with an improved side filler. | 30th Apr 1926 | Box 68 \ 1 scan0274 | |
| Issues with and improvements to petrol filters for 20 HP and Phantom models. | 3rd Jun 1926 | Box 68 \ 1 scan0275 | |
| Confirmation of the use of a standardized new type petrol tank for the 40/50 HP C.2 Series. | 5th Jul 1926 | Box 68 \ 1 scan0276 | |
| Air lock issue in the reserve petrol tank of an 11-EX car, requesting a re-test and explaining the starting procedure. | 1st Aug 1926 | Box 68 \ 1 scan0277 | |
| Revised design of the 40/50 Luggage Grid for the Phantom. | 28th Oct 1926 | Box 68 \ 1 scan0278 | |
| Instructions for chassis modifications, including fitting a new lever cover, petrol tank, gauge, and rear screen. | 11th Dec 1926 | Box 68 \ 1 scan0279 | |
| Modification instructions for the 20-gallon petrol tank on 'C2' Series Phantom Chassis. | 31th Jan 1927 | Box 68 \ 1 scan0280 | |
| Insufficient road clearance for 20 HP and 7-EX models experienced on bumpy roads in France. | 5th Jul 1927 | Box 68 \ 1 scan0281 | |
| Proposal to increase road clearance for Phantom and 20 HP models by modifying the exhaust pipe and rear petrol tank sump. | 9th Jul 1927 | Box 68 \ 1 scan0282 | |
| Design of a spare wheel carrier for the tail of the Phantom model. | 17th Oct 1927 | Box 68 \ 1 scan0283 | |
| Proposing the cancellation of the standardisation sheet for a larger diameter petrol pipe. | 7th Nov 1927 | Box 68 \ 1 scan0284 | |
| Telegauge vent pipe issue and experimental tests with Claudel Hobsons. | 10th Nov 1927 | Box 68 \ 1 scan0285 | |
| Letter from H.M. Hobson Ltd. regarding the function and potential redesign of the vent pipe on Hobson K-S Telegages. | 10th Nov 1927 | Box 68 \ 1 scan0286 | |
| Letter discussing a tank unit fitting and the practice of operating a fuel gauge. | 16th Jan 1928 | Box 68 \ 1 scan0287 | |
| Issue of water accumulating in the main petrol tank, which can render the reserve fuel supply inoperative. | 16th Jan 1928 | Box 68 \ 1 scan0288 | |
| Design and functionality of a Hobson petrol gauge, specifically regarding a new balanced pipe unit and tank casting. | 24th Jul 1928 | Box 68 \ 1 scan0289 | |
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