The engine that came before diesel
On 8 July 1892, a factory on Spittlegate Lane in Grantham recorded its first confirmed sale of a heavy-oil internal combustion engine. The manufacturer was Richard Hornsby & Sons. The engine was not a prototype. It was a commercial product, and it worked.
The invention behind it belonged to Herbert Akroyd Stuart, a Yorkshire-born engineer who filed Patent 7146 in 1890. His design used a heated vaporiser — a separate combustion chamber known as the 'hot bulb' — to ignite timed injections of liquid hydrocarbon without the need for spark or flame. This compression-ignition principle predated Rudolf Diesel's working prototype by several years. Akroyd Stuart had looked for a manufacturer closer to home before bringing the design north to Lincolnshire; Hornsby's Spittlegate Ironworks, already an established engine foundry beside the Great Northern Railway, was the right fit.
Production began in 1891. By the time the run was complete, Hornsby had built 32,417 engines of this type — a total that removes the Hornsby-Akroyd engine from the category of clever experiment and places it firmly in the commercial record. These were working machines, bought and used across Britain and internationally.
Rudolf Diesel's name, not Akroyd Stuart's, became the word the world uses. That outcome was not determined by who invented the principle first. It was shaped by patent law, commercial promotion, and the particular way engineering reputations travel across borders. The gap between what Grantham made and what history remembers is the thread this article follows.
Why a market town could pull this off
Three structural facts explain why Stuart ended up in Grantham rather than somewhere larger.
The first is water. The Grantham Canal, opened in 1797, connected the town to the River Trent and the Nottingham coalfields, giving local ironworks a reliable and relatively cheap fuel supply. Without affordable coal, foundry work at scale was not economically viable; with it, Grantham could sustain heavy manufacturing that other market towns could not.
The second is rail. The Great Northern Railway reached Grantham in 1850 and extended its reach to the Spittlegate site by 1852. That connection turned local production into exportable production. Finished engines could move to customers in Britain and abroad without the canal's slower freight rhythms constraining the business.
The third is prior depth. Richard Hornsby & Sons had been making agricultural implements since 1828. By the time Stuart came looking for a commercial partner, Hornsby had built what contemporaries described as a near-monopoly in portable steam engines — meaning the firm already had pattern-makers, foundry staff, a quality record, and an established export mindset. Stuart was not asking a willing amateur to take a risk; he was approaching a manufacturer that already knew how to build precision mechanical equipment at volume and move it to distant markets.
Grantham was not an improbable location for the world's first commercial oil engine. Given those three conditions, it was a logical one.
One firm's reach — from engines to tracks
The oil engine was Hornsby's most consequential product, but not its only one. Working independently, the firm developed an early caterpillar-track system for vehicles — a traction mechanism designed to spread weight across soft ground — and sold the patent to Holt & Co. in the United States. Holt's subsequent development of tracked vehicles contributed to the technology strand that produced the military tank during the First World War. Hornsby was not the inventor of the tank, and the causal chain runs through several hands; the point is that a second line of global consequence originated from the same Spittlegate foundry.
At its peak, Hornsby employed approximately 2,000 people in Grantham. For a Lincolnshire market town, that figure represented not just an employer but an economic centre of gravity: a place that trained engineers, sustained supply trades, and shaped the working life of a large share of the town's population.
The firm's independence did not survive the post-war settlement. In 1918, as consolidation swept through British agricultural engineering, Hornsby merged with Ruston & Proctor of Lincoln to form Ruston & Hornsby. Nearly a century of manufacturing under the Hornsby name ended. The Spittlegate site, however, did not fall quiet.
How Grantham lost the naming rights
Rudolf Diesel filed his own compression-ignition patent in 1892 — the same year Hornsby recorded its first commercial sale — and moved quickly to exploit it through licensing agreements with European manufacturers backed by substantial industrial capital. The result was not a better engine so much as a better-distributed name: 'diesel' travelled through licensing contracts and commercial promotion into the vocabulary of engineers, buyers, and eventually the general public, while the Hornsby-Akroyd engine remained a British trade name tied to a single Lincolnshire foundry.
What Akroyd Stuart had demonstrated first — fuel ignition by compression and heat, without spark — became attached to Diesel's name through that commercial machinery, not through any technical reappraisal of priority. Those tens of thousands of engines built and sold from Spittlegate simply existed in a vocabulary that someone else had come to own.
For Grantham, the consequence is a specific kind of invisibility. The town produced a globally diffused technology at commercial scale, and the word that technology carries erases it entirely. This is worth sitting with analytically rather than treating as a complaint: the naming outcome shows how industrial credit actually works — not through who demonstrated the principle first, but through whoever captures the language and controls its spread. The gap between what Grantham made and what mainstream industrial history records reflects a contest the town was never equipped to enter. It simply built the engines.
Spittlegate after Hornsby — the site's second industrial life
Thirty acres of the Spittlegate site did not stay idle long. In 1934, Aveling-Barford — itself the product of a merger between Aveling & Porter of Rochester and Barford & Perkins of Peterborough — relocated its entire operation to Grantham's Invicta Works, moving plant and equipment by rail. The firm made road-construction machinery: rollers, graders, and dumper trucks.
The scale it reached was considerable. By the late 1930s, Aveling-Barford's Grantham plant had become the largest specialised road-roller factory in the world, producing over 75% of Britain's road rollers and exporting across international markets. The machines were different, but the industrial geography was the same — and so was the underlying technology thread. Aveling-Barford's rollers transitioned from steam power to diesel, the compression-ignition principle that Hornsby had first manufactured commercially on the same ground four decades earlier.
The pattern that ended Hornsby's independence in 1918 repeated itself in 1967, when Aveling-Barford was absorbed into British Leyland's Special Products Division. Large-scale independent manufacture on the site ended for a second time, following the same consolidation logic that had swallowed its predecessor.
Grantham's engineering cluster today — what the evidence actually shows
Slip rings for offshore wind turbines, alternators for power generation, VHF communications equipment for air traffic control: the engineering employers present in Grantham today represent a genuinely diverse technical range. BGB, Cummins Generator Technologies, and Park Air Systems work in distinct sectors, but together they give the town a recognisable engineering identity that extends well beyond any single industry.
Whether that identity reflects genuine continuity of local engineering culture — something transmitted through skills, supply chains, or industrial memory — or simply a coincidence of site costs and geography, is genuinely open. No mechanistic link between Hornsby's era and today's employer location choices has been demonstrated. Grantham College's Energy Centre connects vocational training to this employer base — the town is not merely inheriting a reputation but actively reproducing technical skills — yet how deep that pipeline runs, and what draws firms here rather than elsewhere, remains a live civic question rather than a settled one.
What industrial heritage does leave behind is something more modest but real: a legible identity. A place that built 32,417 compression-ignition engines before the word 'diesel' existed, and then housed the world's largest road-roller factory on the same ground, has something specific to argue from — not a guaranteed economic succession, but a particular account of what this acre of Lincolnshire has been capable of building.
- [1] Hornsby–Akroyd oil engine. https://en.wikipedia.org/?curid=13408158 https://en.wikipedia.org/?curid=13408158
- [2] Hot-bulb engine. https://en.wikipedia.org/?curid=5326405 https://en.wikipedia.org/?curid=5326405
- [3] Richard Hornsby & Sons. https://en.wikipedia.org/?curid=3054919 https://en.wikipedia.org/?curid=3054919
- [4] Aveling-Barford. https://en.wikipedia.org/?curid=4983662 https://en.wikipedia.org/?curid=4983662