HM Factory, Gretna (His Majesty’s Factory), was a World War I munitions factory located in Southern Scotland next to the Solway Firth, Dumfries and Galloway.
Described as “the biggest factory in the world”, it was 9 miles long, 2 miles wide, and stretched from Eastriggs in the west, past Gretna and across the Scottish/English border to Longtown in the east.
Munitions production started in April 1916. By 1917 the factory was employing 11,576 women and 5,966 men.
At its peak the factory produced 800 tons of Cordite RDB per week, more than all the other munitions plants in Britain combined.
The site was chosen for its remoteness from populated areas, but good access for services and supplies, which still holds true for a number of military facilities located in the surrounding area today. It would also prove difficult for the Luftwaffe to reach, and the area itself provided natural cover, with the sea air and mist from the surrounding hills combining to obscure the site from the air.
Codename Moorside, the factory was built to produce Cordite for the British Army in response to a shortage of shells on The Front. As early as 1915, British and Allied troops were reported to be suffering enormous losses as their artillery was starved of ammunition, while their adversaries had no such problems. Although the Allies had the artillery to support their operations, its Cordite propellant was in short supply, the reserves of acetone required for its production were simply not available. Acetone was produced by distillation from wood, itself a limited resource, and also in demand. The breakthrough came when a process for producing acetone by fermentation, previously considered to be of little value, was scaled up and used to replace the wood distillation process, allowing acetone to be produced from grain, an annual crop.
Production began with Cordite RDB (Research Department formula B), but was later switched to Cordite MD (MoDified) as wood-based acetone availability improved. The RDB variant was found to become unstable if stored for long periods.
Numbers associated with the factory were impressive: 800+ tons of ammunition produced per week; 30 miles of road; 100 miles of water main; 125 miles of railway track; 34 railway engines; water treatment plant handling 10 million gallons each day; power station for the factory and towns; telephone exchange handling 2.5 million calls; bakeries producing 14,000 meals and 13,000 loaves; laundry for 6,000 items per day. The factory employed 20,000 workers , a number which peaked at 30,000 during construction.
To accommodate the workers, the first government sponsored new town in Britain was created within the site, Gretna – the first such town to be sponsored in the 1900s, which was quickly followed by the smaller village of Eastriggs a few miles to the west. Until they were completed, the huge number of workers was accommodated in surrounding towns and villages, resulting in what would now be referred to as hot bed working. Familiar to workers on offshore oil platforms, this means organising working and sleeping into shifts, so that as one worker leaves their accommodation to start work, another is coming off shift to take their place, thereby maximising use of the available facilities.
After World War I ended, the factory was dismantled. Despite the huge size of the operation, almost nothing remains of its construction other than a few anonymous building remains and foundations. Although it covered a large area, the layout would have been relatively sparse, and construction lightweight. This would ensure sufficient distance between buildings to avoid a chain reaction if there should be an accident in one, and to minimise the effects of flying materials in the event of an explosion.