The Praga RN (Czech: Rychlý Nákladní, “fast freight”) was a medium-sized truck launched by Praga in 1933 and powered by a six-cylinder petrol engine. From 1934 it was joined by the diesel Praga RND, and the two, manufactured for nearly three decades, became among the most widely used freight vehicles in Czechoslovakia.
Praga RN at a glance
| Maker | Praga, Prague-Libeň |
|---|---|
| RN production | 1933–1953 |
| RND production | 1934–1955 |
| RN engine | 3,468 cc side-valve six, 52 hp (38 kW) |
| RND engine | 4.5-litre OHV four diesel, 50 hp (37 kW), 60 hp (44 kW) from 1946 |
| Payload | 2,000 kg, 2,500 kg from 1937, 3,000 kg after the war |
| Fuel consumption | 25 l/100 km (RN), 15 l/100 km (RND) |
| Gearbox | four-speed, non-synchromesh |
| RN built | 23,747, including about 2,100 buses |
| RND built | 16,288, including 1,630 buses |
| Licence production | 18,300 built in Yugoslavia as the TAM Pionir |
| Total | about 40,000 RN and RND |
History of the Praga RN
Praga launched the RN in 1933 as a conventional medium-weight truck: rigid axles, a sheet-metal cab over a wooden skeleton and a ladder frame. Initial production numbered 94 vehicles, half of them built in 1934. In 1937 a larger carburettor raised output from 38 kW to over 50 kW and payload from 2,000 to 2,500 kg, together with a slightly rounded, more modern cab. A more radical redesign followed in 1938, with a radiator of fashionable horizontal vents, and that shape then stayed unchanged for nearly twenty years.
The efficiency of the diesel engine and the lower price of its fuel led Praga to build four test vehicles with a four-cylinder diesel in 1934 and 1935, named RND, the D standing for Diesel. More test vehicles followed, then an initial run of sixty trucks in 1937. Production of both types continued through the war, with wood-gas generators of the Imbert or Janka type fitted instead of the petrol engine, until Allied bombing damaged the Libeň works on 25 March 1945. Production resumed in a new plant in Vysočany, at first with wood gas; a reinforced frame raised payload to 3,000 kg, and the RND returned in 1946 with a Ricardo Comet III chamber that lifted output from 37 to 44 kW and cut fuel consumption.
The last RN was built in 1953, after 48 series and 23,747 vehicles including about 2,100 buses; the RND reached 16,288 by 1955, including 1,630 buses, in 38 series, and the two together came to about 40,000. The RN was nicknamed Erena and the RND Randál, a phonetic derivative of the initials that also commented on its noisy engine. In 1938 the Kingdom of Yugoslavia chose the RN in a competition that required an 8,000 km journey over poor roads, and the ZAR works near Belgrade began assembling parts, with the first Yugoslav vehicle completed in 1940. Production resumed in 1947 as the Pionir and moved to Maribor, where 17,146 TAM Pionir trucks were built until 1962, for 18,300 in all. No equivalent replacement appeared, so RN and RND trucks served into the 1970s.
Design and features
- Two fuels, one truck: the petrol RN and diesel RND shared a chassis and all later improvements.
- Progressive modernisation: more power and payload in 1937, a new radiator in 1938, a reinforced frame after the war.
- Every body imaginable: flatbed, tipper, tanker, refuse truck, fire engine and bus on the same chassis.
- Licence success: the RN won a Yugoslav competition and was built there as the TAM Pionir until 1962.
Praga RN versions
- Praga RN (1933–1953): 3,468 cc petrol six, flatbed as standard.
- Praga RND (1934–1955): 4.5-litre diesel four, 50 hp then 60 hp.
- Wood-gas versions: Imbert or Janka generators during and just after the war.
- Buses: about 2,100 on the RN and 1,630 on the RND chassis.
- Fire engines and municipal bodies: built on both chassis.
- TAM Pionir: Yugoslav licence version, 17,146 built in Maribor to 1962.
The RN was replaced in production by the Praga V3S, and its road-going derivative was the Praga S5T. More vehicles are in the Praga collection.
Video: Praga RN fire engine in action
Video on YouTube.
Sources
- Praga RN, English Wikipedia: history, drivetrain, Yugoslavia, nicknames
- Praga RN/RND, Czech Wikipedia: series, production figures, RND engine, post-war production
