e. V. or DGEG) in Neustadt an der Weinstraße on the 'wine route' where it can be viewed. The last of these engines, no. 18 508, is in private ownership and stabled in Switzerland. (Locorama Romanshorn). Series l, m, n and o Because the production of standard locomotives was not envisaged in the first numbering plan and because the upgrade of main lines to 20 tons was proceeding very slowly, the Deutsche Reichsbahn ordered more Class S 3/6 locomotives from Maffei. In 1927, 12 units of series l were delivered (18 509–520); in 1927–28 they were followed by eight engines of series m (18 521–528). Compared with series k, the superheater was somewhat larger again; in addition, the diameter of the high-pressure cylinder was increased from 425 mm to 440 mm. Several series m locomotives were supplied to Wiesbaden shed in order to haul important trains. Of the 20 planned locomotives of series n, Maffei could only deliver 2 engines (18 529 and 530) before it went bankrupt. Henschel took over the order and supplied the rest of the 18 engines in 1930–31 as series o (18 531–548). The last 11 locos of this series were given a newly developed tender with the designation 2'2' T 31.7. No. 18 528 is preserved and stood as a memorial in front of the HQ building of the former Krauss-Maffei company in Munich. The locomotive is now in a shelter in the grounds of the Allach factory, following the takeover of the former Krauss Maffei Transport Technology by Siemens, and is not accessible to the public. Deutsche Bundesbahn In the 1950s a large part of the Deutsche Bundesbahn's vehicle fleet underwent modernisation. As a result, 30 Class 18.5 engines were rebuilt by the firms of Krauss-Maffei and Henschel. These were the series l to o locomotives built for the Reichsbahn between 1927 and 1930. These units were given a newly developed replacement boiler with combustion chamber at the Ingolstadt and Munich-Freimann repair sheds by the Minden engine shed and Krauss-Maffei. In addition the locomotives were given a new driver's cab and multiple-valve superheated steam regulator. Further planned modifications, such as new cylinder blocks, were not carried out. The rebuilt locomotives placed in service between 1953 and 1957 were given the new operating numbers 18 601–630 and were used in express train services, where they almost matched the Class 01 in their performance. They