sentences:  However, in their use of a leading radial axle, rather than a Bissell truck, and other features, they were more conventional examples of mid-Victorian locomotive design than the Isle of Man Railway's Beyers.Boyd mentions that they were tested at speed before their entry into service and officially restricted to 45 mph.There have been some suggestions that their shorter wheelbase, 11'6" as opposed to 13'9" for the Beyer Peacock locomotives, made their ride less than steady at higher speeds.