During our week in Prague I spent one day chasing rail related goals. I visited the NTM to see the steam locomotives there.
1 The Czech National Technical Museum is housed in an unimaginative building. It contains a host of collections, a bit of everything. But most importatnly, it contains four steam locomotives three of which are serious exhibits.
2 The first steam locomotive is KLADNO from 1855, built to the Engerth system. It was supplied to the company of Bustehradska railway (BEB/BD) and included into the category I under the number 103. The locomotive was used mainly for transport of coal. The design to system of Wilhelm Engerth allows the tender to bear a part of the locomotive boiler weight. Only three standard gauge locomotives of the Engerth system have been preserved, the other being Ec2/5 "Genf" (status : operational!) and the other is Midi 0-6-4T locomotive no.312 L'Adour in the Cité du Train Museum in Mulhouse France, which I photographed in 2014.
9 Remarkable are the vertically orientated external flat slide valves on the cylinders. Normally the valves are placed above the cylinders.
10 The valve gear is of the Gooch type, which is very similar to the Stephenson valve gear.
11 A funny construction is that the valve is not operated directly but over two cantilevers. For the world I cannot figure out why this was done. The only thing I can think of that it was done to bridge the gap to the outside valves which lie very far out of the plane of the valve gear.
12 This is where the two cantilevers are joined.
16 The articulated tender construction can clearly be seen here. Strictly this Engerth is not an articulated steam locomotive as the definition thereof requires one or more powered axles to be incorporated in the articulated part. The original Engerth concept was an articulated steam locomotive in the strict sense when the tender axles were powered over a chain drive. But due to the rapid wear of the chains and the sprockets that construction was quickly abandoned.
17 It can easily be understood that the tender bears part of the locomotive weight.
21 This engine from 1881 was designed to pull fast express trains. To obtain high speeds large wheels were provided, although by standards of fifty years on they were not exceptional (1900 mm). The locomotive saw service until 1931.
24 The locomotive clearly sports characteristic Austro-Hungarian design details, like the split and flat smokebox doors and the large external steam pipes. Special for this design are the double frames (both internal and external)
29 The excentrics of the Stephenson valve gear are huge.
31 Clearances between the exentrics and the other moving parts are tight.
44 The rear wheelset prenetrates deeply into the drivers cab which must have been a nuisance during operation, especially for the firman who had to step over the splasher twice for every shovel of coal. Other than that the cab is very spacious.
45 A view form the fireman's side.
49 My real reason to come to the NTM was this Austro-Hungarian noblesse. The Express locomotive of the later Czech class 375 was designed by Gölsdorf after his sucessful Atlantics. The KkStB class 310 as it was called in 1910 was his masterpiece in effectivity as well as in beauty. 90 were built between 1911 and 1916. Two survived, 310.25 in operational condition in Austria and this static one in Prague.
50 After WWI the class of 90 was divided over the various countries that took posession of the remains of the Austro-Hungarian Monarchy. Just 43 remained in the newly formed Austrian Republic, 12 went to Poland and the remaining 35 went to Czechia where they were renumbered into 375.001-035. They were used until 1954. This engine was added to the national collection in 1955.
54 The front of the locomotive clearly shows the four cylinders.
55 They proved to sustain a load of 400 tons at 100 km/h, delivering some 1800 hp.
61 The injector
62 Driver diameter 2140 mm!
66 The spacious cab.
69 Note that four control bars are located in the horizontal plane, thus reducing the visual clutter.