R.o.B Motive Power
GWR Iron Duke Class 4-2-2
Specifications: 4-2-2 Iron Duke Class built by GWR and Rothwell & Co of Bolton 1847-1851 & 1854-1855
Tractive effort: 8262lb
Cylinders: (2) 18in x 24in
Driving Wheels: (2) 8ft 0in
Steam pressure: 100lbpsi increased to 115 later engines having 120lbpsi boilers
Fuel/Capacity: 1ton 10cwt (originally coke burners)
Water Capacity: 1760 gallons later increased to 1880 some had 2700 gallon tenders
Total Weight: 35 tons 10cwt locomotive 17tons 4cwt tender
Valve gear: Gooch
Grate area: 21.7sq ft
Heating surface: 1,954sq ft
Designed By: Daniel Gooch
When first built these broad gauge locomotives were the pride of the GWR the engines were designed specifically for the conditions of the railway. Previously the company had bought different types of locomotive, by Daniel Gooch who had taken up his position as GWR engineer in 1837. The class emanated from Gooch's other successful 'Great Western' class 2-2-2 which were converted to 4-2-2 after several weight distribution problems. The locomotive 'Great Western' had achieved 74.5mph in the June of 1846 with one of the one of the class, 'Great Britain' achieving a top speed of 78.2mph at Wooton Bassett on 11th May 1848. The 'Iron Duke' class were named after battles in the Crimean war. The fireboxes were of the domed Haycock type with boilers of 11 feet long with a 4 feet 9 1/2 inch diameter containing 303 tubes. To allow speedier services and non stop runs from Paddington to Swindon the class were given larger tenders capable of holding 2700 gallons. This saw the engines regularly see 60mph for the 53 mile section of line from Didcot to Paddington. Twenty four of the class were re-built between 1871 and 1888 effectively creating a whole new locomotive with little of the original remaining. A new class name of the 'Rover' class being formed. Despite the conversions some of the original class did remain one of which 'Lord of the Isles' was preserved by the GWR but was broken up by the company in 1906 with no official reason why. With the 150th celebrations of the GWR in 1985 a replica of the 'Iron Duke' was built and operated on a purpose built section of Broad Gauge track laid in Kensington Gardens near Hyde Park, London from April 1985. Normally the engine can be found at the National Railway museum that has a purpose built running line in the new former goods depot.