4-8-4+4-8-4 classes of 4-8-4+4-8-4 steam locomotives across the globe, all of which were constructed by Beyer, Peacock and Company, the owners of the Garratt patent. The predecessor 4-8-2+2-8-4 Double Mountain was probably the optimal Garratt wheel arrangement, with the four-wheeled leading bogies and the two-wheeled trailing trucks on each engine unit ensuring stability at speed and with sixteen coupled wheels for traction. More coupled wheels would inhibit the locomotive on tight curves, while the only advantage of more non-coupled wheels, such as on the Double Northern, was to reduce the axle loading. The second Double Northern locomotive class were the AD60
How 2 was featured on the "30 Years of CITV" documentary that aired on ITV on 29 December 2012 and featured interviews with Dinenage and Jones. The last episode of the series was a 30th anniversary special. Before that, there was "The Best of How 2" which aired on 18 August 1997. There was no series aired in 1998 but there was a spin-off series called "How Goes 2", which aired from 25 February to 15 April 1998. The series focused on Fred and Gareth going to different places each week, and the 8 shows featured segments from the first 6 year