Suitable for:
	the SFMES 13.6 mm, (0.535″) tyre width and 3.2 mm, (0.130″) flange depth.
	or the GL5 standard of 12.7 mm, (1/2″) tyre width and 3.97 mm (5/32, 0.156″) flange depth
 
	For  5½″ tyre width at this scale use 12.4 mm, 0.487″.		
	
			
		4′ 0″ diam. (originally 3′ 11″), 12 rectangular spokes, low slightly humped inner rim. 
		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: 108.0 mm tread dia., 89.2 mm i/d., hub 1.7 mm out from the tyre.
(= 4.251″ tread dia., 3.512″ i/d., hub 0.067″ out from the tyre.)
Casting prices and stock . 5 inch gauge loco sets, price list
Scan of a casting in a set for a GN 4-2-2 with prototype photographs.
	
	27 Mar 2013