Mixed results from ‘GlosWarks’ ovoid trial
TRIALS OF ovoids – a manufactured solid fuel being promoted as an alternative to traditional coal – produced mixed results at the Gloucestershire Warwickshire Steam Railway, with two locomotives running out of fuel.
The line has traditionally sourced its coal from Ffos-y-Fran surface mine in South Wales, supplies from which ended suddenly in late January owing to a breakdown of the mine’s grading and washing plant. The GWSR has been able to secure one-off deliveries of Colombian and Eastern European coal to tide it over, but with Russian coal supplies affected by the Ukrainian conflict, the railway opted to trial ‘Trevithick Steaming Ovoids’ from its primary supplier, Hargreaves Services. These are made from Neath anthracite fines bonded with lime and, unlike Ffos-y-Fran coal, have no bituminous content.
Trials were conducted on March 12 with all four of the line’s locomotives, with Nos. 7903 Foremarke Hall and 35005 Peninsular & Oriental S. N. Co. used specifically for testing, and Nos. 4270 and 7820 Dinmore Manor on service trains.
“This was, to be fair, something of a challenge,” said Adrian Showell, the line’s steam department’s buyer. “Raising steam in the first place used significantly more fuel than Ffos.
“It quickly became clear that the material needed a constant draught to burn well, and the engines were burning rather more than with Ffos. It needs a completely different firing technique, which will be a learning curve for many of our firemen. It also produces a lot of fine ash, which had a tendency to clog the firebars, suggesting wider firebar spacing might be needed. There was a lot of char in the smokebox, too.”
Fuel consumption was higher than traditional coal too, and Nos. 4270 and 35006 both ran out of coal during the trials and needed rescuing. “We are feeding this information back to our supplier and the recipe for the material is being tweaked – it will be interesting to see how this develops,” said Mr Showell. The railway has since used a mix of one-third ovoids and two-thirds coal on its trains, and this has worked well.
He added: “The GWSR is secure in terms of fuel supplies at present so there is no immediate threat to our advertised steam train services. Nevertheless, the cost of fuel will rise in future (this applies to diesel fuel as well) and our footplate crews will be on a learning curve in order to handle the different materials in the most economical way and with minimum production of smoke.”