 Since the proponents of the scheme had a slogan about electric trains accelerating to thirty miles an hour in thirty seconds, Holden resolved to obtain the same performance with steam traction.A massive boiler with Wootten firebox, three cylinders each with its own blastpipe cone, and ten smallish driving wheels ensured a lively acceleration.On trial it did rather better than 30 mi/h (50 km/h) in thirty seconds, accelerating at 1.46 ft/s² (0.45 m/s²)