4′ 0″ diam. (originally 3′ 11″) , 12 rectangular spokes, low slightly humped inner rim. 
Tyre width originally 5″ measured
		in 1995 as 5½″.
		Hub: 12″ face dia., ¾″ out from the tyre.
			
		Sources: measurements direct from preserved loco No. 1 at NRM, York, June 1995. 
		The Stirling Singles, Leech and Body, David and Charles (1965), page 53. (Tyre width).
		Great Northern Locomotive History, RCTS.,  vol. 2 page 164. (Wheel diameters).
Casting: 40.0 mm tread dia., 33.1 mm i/d., hub 0.6 mm out from the tyre.
Casting prices and stock . GN loco sets, price list
Scan of a casting in a set for a GN 4-2-2 with prototype photographs.
	
	27 Mar 2013