The locomotive was also equipped with a Watson cab with its distinctive inclined front. Despite the specifications, the first batch of Class 19D locomotives, built by Krupp and Borsig and delivered in 1937 and 1938, came in two variations. The Krupp-built locomotives were delivered with domeless boilers, while the Borsig-built locomotives conformed to the specifications with domed boilers. While the domeless boilers did not conform to the specified Watson Standard no. 1A boiler as far as the dome was concerned, they were accepted nevertheless, probably since all their other dimensions were identical to that of the Watson Standard boiler. It appears that Krupp had decided on their own accord that a dome was not necessary since there was no regulator in the dome, but merely a standpipe. Krupp substituted the dome with a manhole cover on which the two Pop safety valves were mounted, while the steam was collected through a battery of collecting pipes, situated high up in the boiler in a similar manner to that which was used in the Class 16E. All the subsequent Class 19D orders were delivered with domed Watson Standard no. 1A boilers with the usual standpipe steam collector high up in the dome, from where steam was led to the multi-valve regulator in the smokebox. Technically, whenever the loading gauge permitted the use of domes, their use was preferable to the domeless system which resulted in crowding multiple pipes into the boiler and other complications better left out of boilers. Operationally, according to drivers, there was no apparent difference in locomotive performance between the two boiler types. The Watson Standard boilers are interchangeable between locomotives. In the process of locomotives undergoing major overhauls, these twenty Krupp-built domeless boilers migrated between engines during subsequent years. As a result, locomotives from the other builders and even some Classes 19A and 19C locomotives eventually ended up with some of these domeless boilers. Tenders As a result of having been built over such a long time span by so many different manufacturers, the six main groups of the Class 19D all had different all-up weights and axle loadings, as shown in the table and the specifications in the infobox. Over the eleven years during which the Class 19D was being produced for the SAR, some alterations occurred. As built, the Class 19D was delivered with Type MT tenders with a coal and a water capacity, even though