The majority of saddle tanks were rebuilt with pannier tanks from 1902 onwards. The vehicles straddled the rail, rather like a pair of pannier baskets on a mule. Some 5700s also had white and red lining on the pannier tanks and cab sides. Pannier tank locomotives are often seen as an icon of the GWR. The modern bicycle pannier was invented by Hartley Alley (1919-2001) of Boulder, Colorado, in 1971. In Britain, Pannier Tank locomotives were used almost exclusively by the Great Western Railway. The earlier form of the pannier took the shape similar to a 19th-century crinoline. There were numerous other classes of pannier tanks built by the GWR. "Corbicula" is a diminutive of "corbis", a basket or pannier. The locomotive used was Pannier 5775 in its London Transport guise as L89. The whole series was later rebuilt again as pannier tanks. Most were reconstructed with pannier tanks from 1911 onwards. The Georgian Guildhall is also of interest as well as the Pannier Market beneath. Collett had to produce a new standard design for 0-6-0 pannier tanks. The indoor Pannier Market is open all year with many stalls and small businesses.