The rim style used on higher-end Raleigh 3-speeds. The Raleigh pattern rim was similar to the Westwood rim, except that it had flat sides and square corners, so it could be used with either caliper brakes or rod brakes. It may have been the strongest rim ever made. This style of rim is most commonly found in the 590 mm (26 x 1 3/8) size and smaller.
Raleigh pattern rims are sometimes also referred to as "Westrick", which is a made-up word combining "Westwood" with "Endrick." Westwood rims were only for use with rod brakes; Endrick rims were only for use with caliper brakes; but Raleigh Pattern, a.k.a. "Westrick" rims can be used with either type.
They combine the raised (or dropped, depending how you look at it) center that keeps rod brake shoes free from the risk of hitting the spokes, with the flat sides required for rim brakes.
Raleigh Pattern rims are preternaturally strong, probably the strongest bicycle rims ever made. However, like all steel rims, they can get bumps on the sidewalls from pothole impacts an the like.
..So possibly pretty damn good, depending on what tyres were available.