Siemens Industrial Turbomachinery Ltd in Lincoln, England recently turned to 3D scanning and additive manufacturing technologies to restore a hundred-year-old Ruston Hornsby motor car. The car, originally introduced in 1920, was one of the first products released by industrial equipment manufacturer Ruston & Hornsby Limited, now part of the Siemens Group.
Towards the end of World War I, Ruston & Hornsby Limited was formed through a merger between Lincoln-based Ruston, Proctor & Co and Grantham-based Richard Hornsby & Sons. The new company, which drew from Ruston’s expertise in oil and diesel engines and Hornsby’s heavy oil engine manufacturing, sought to diversify its business after being responsible for aircraft manufacturing during the war.
Part of this diversification—which was necessary to keep its business booming after the war—was the manufacturing of the Ruston Hornsby motor car. The luxury vehicle came in two versions: a 15.9 hp with a Dorman 2614 cc engine and a bigger 20 hp version with a 3308 cc engine made by the company. Both models could optionally be fitted with a 4” high brass Lincoln imp radiator mascot upon customer request.
Designed and built by Ruston & Hornsby’s experienced engineers, the motor car model boasted a solid and well-built structure. A downside to this quality was the car’s heavy weight (both models were built on a 9” chassis), which inevitably drove up its cost. The car, whose price varied between £440 and £1000 (about £18,695 to £42,490 today), was much costlier than other, mass-produced models on the market, which weighed significantly less and only costed about £120 to £200.
Because of this, Ruston & Hornsby only had a limited run of making cars, stopping its motor car production in 1925 after about 1,500 cars were sold.
More recently, however, to mark 100 years since the formation of Ruston & Hornsby Limited, Siemens undertook a project to restore two of the original motor cars which were being stored at its Lincoln facility. The site, now primarily used for the design, development and production of small industrial gas turbines, has hosted an extensive restoration effort on the part of apprentices and dedicated volunteers.
The two car models that underwent restoration were thankfully still equipped with many of their core components—both their engines and major parts were still mostly intact. But the restoration teams struggled with finding smaller, ancillary parts and running components which haven’t been in production since the 1920s. To add to the challenge, much of the manufacturing information for the motor cars had been lost.
One critical part that needed replacing was the Steering Box on one of the cars, which had suffered damage and was broken into several pieces. “We could have a new part machined from solid metal,” reads a Siemens article on the restoration. “But we had no drawings! Added to that is the fact that most machine shops don’t want to manufacture a one-off part due to lengthy design and set-up times which prove costly.”
Fortunately, a team from Siemens Materials Solutions was able to leverage 3D scanning technology to digitally restore and create a full model of the Steering Box. By reverse engineering the vintage part, the team was able to produce a 3D model primed for 3D printing.
Using a metal powder 3D printer, the team was able to reproduce the Steering Box in just five days—two and a half years faster than if they had resorted to an external machine shop. In addition to the convenience of producing the part more rapidly, the restoration team also says the metal 3D printed part was more accurate than a traditionally manufactured part would have been and was more robust because it was engineered as a single piece.
With the restoration nearly complete, Siemens is preparing to debut one of the Ruston Hornsby motor cars with a test run at Cadwell Park later this year. After the test run at the famous motor racing circuit in Lincolnshire, the car will be put on display at the Festival of Speed event at Goodwood.
“Not only does the restoration of the cars demonstrate our commitment to celebrating the past, preserving our engineering heritage and engaging with the community, the project is also about inspiring the next generation of engineers,” writes Siemens. “This is a great example of how a 100 year old car can get back on the road with the help of cutting-edge technology!”