The Škoda 706 truck has a very long tradition and the first examples appeared in 1939. The car replaced the type 606 and was replaced by the type 706 R before the end of the war. But the more iconic model is the 706 RT, which first appeared in 1958. They were used for it is nicknamed erők or trambus, but in fact the abbreviation means “reconstructed trambus”, although some mistakenly consider the abbreviation R to mean “frame”. The number 70 then means the load capacity in metric cents and the 6 again indicates the number of cylinders in the engine. The 706 RTH was intended for a sprinkler truck, the RTP was a flatbed with four-wheel drive (P for attachable front-wheel drive) and the RTHP was a fire tanker with four-wheel drive. The abbreviation CAS stands for tank car sprayer, the number 24 indicates a pump with a capacity of 2,400 liters per minute. This hopefully clears up the name and we can look at other interesting things.
The LIAZ design office was established in 1953, and already in 1955 the first prototype of the RT model was created on the 706 R chassis, which was shortened by a meter. Nevertheless, the name Škoda still remained for the car, as it was better known on export markets. The prototype already had a modern non-tilting rounded trambus cabin, which was fully comparable to the Western production of the time, and was even considered one of the most beautiful. Until then, the last truck with a trambus cab and the Škoda brand was the steam-powered Sentinel, which was produced in Pilsen under a British license. The fire engine variant offered an extended cabin for six people. It can fit up to eight in an emergency. Officially, it is indeed stated as 7+1, but that must not be the firefighters in the big emergency suit. The strike commander sits in the front passenger seat, where I also begin our drive before I’m allowed to try my hand at the wheel. It is from this seat that the dual-zone heating is controlled. There are additional storage spaces under the seats.
Behind the cabin is a superstructure, sheeted with a steel frame. In its bowels is a tank for 3,500 liters of water, which the floating pump fills in 4 minutes. But you have to drive either full or empty. Even if there are partitions in the tank, if there was only half of the water in it, the tank would be quite difficult to control in turns, maybe even dangerous. On the sides of the superstructure there are lockers for equipment – hoses, jets, pump, breathing masks, but also axes, saws, shovels, brooms, tools, ropes, crowbars, power plant and portable reflectors. On the roof there are ladders and also a water cannon, i.e. properly a rotating gun carriage. The tank can be sprayed with it in no time, but it is said to be used a few times a year during field fires. For the most part, firefighters hook up the hoses and direct the current to where they need it, rather than aiming for a distance. But spraying from a superstructure is great fun and I wish you could try it at least once in your life. The exhaust pipe was originally under the pump so that water would not freeze in it in the winter, but then it opened under the car. Here, however, it is brought up to the roof of the superstructure behind the pump, so that the fumes do not get in the faces of the firefighters connecting the hoses. Discharges are redesigned for levers, which work more reliably than rotary ones.
In the cabin, under a massive cover between the seats, sits a modernized in-line six-cylinder OHV diesel engine with direct fuel injection, which was a novelty compared to its predecessor. This made the engine more powerful and reliable. Its volume is a respectable 11,781 liters and it offers 160 horsepower (118 kW) at 1,900 rpm. The radiator is right behind the front mask, and the beautiful lid for filling it is right under the windows. The wipers on them can be controlled individually.
Driving takes practice
The engine is connected to a manual five-speed gearbox with a dog leg and already with a dry single-disc clutch. Here, of course, it is not for sportiness, but for a purely practical reason, when the first gear is for off-road or hill starts, and on the road you can easily start with the second gear. Reversing the hill with the car jumps quite a bit, but when you engage all-wheel drive, the car reverses smoothly. This transmission only has synchros higher than three, so it needs to be able to shift gears, or to quickly learn intermediate gears. Trambus simply won’t forgive this. I won’t lie and admit that I also miscalculated the teeth, but in the end, thanks to Marcel’s (he’s the driver of this beauty in the choir) instruction, I got used to it and managed to change gears smoothly. Well, he’s a good instructor and he likes the erták very much. After all, he was the first in the current choir to manage the climb to Hůrek. The lever is beautifully long and the gears are also long. Conversely, the gas pedal is small and close to the center cover.
All wheels are driven, which the name of the car reveals. The first Škoda 706 RTP with 4 × 4 drive was produced from 1964. As standard, the torque only goes to the rear axle with a double mount and differential lock. You have to connect the front one with the additional differential lock manually with the rotary switch under the dashboard. There is a flat steering wheel above the switches, the steering is worm and equipped with an air booster, but it has quite a lot of play. You will still exercise your muscles. The single-circuit brakes are drum, but the Škoda of course has an engine brake, where you throttle the engine a little by preventing the exhaust fumes from being drawn off. But it cannot be used all the time, then the seal under the head suffers.
He’s no sprinter
The trambus in the fire engine version can drive empty up to 90 km/h, but with a full tank it will drive for a long time at more like 80 km/h. At the same time, 60 is quite unusual with a full tank and it seems much faster. The average consumption is 24 liters per hundred kilometers (plus a few deciliters of oil), the tank holds 175 liters. Ride and handling are also improved over the previous 706 R, as the center of gravity is lower. The chassis frame is shorter and lighter, carries rigid axles with longitudinal leaf springs, and even the typical Trilex wheels are smaller (twenty-inch, while the previous 706 R was two inches larger) and lighter. The result is a curb weight of 9,200 kilograms and a useful 4,370 kilograms.
Liazka won’t get lost even in lighter terrain, and that’s not only thanks to the all-wheel drive. After all, Marcel doesn’t even turn it on in the lighter one. The car also has a decent approach angle of 32 degrees. It’s worse at the back because of the overhang, but even 17 degrees is not a bad value. Ground clearance is 280 millimeters. At the same time, the Škoda 706 was never designed specifically for off-road use, that’s what Tatras and Prags were made for. However, the left back can handle interventions in the forest and in the field. Russian Kama tires with a more pronounced pattern help in this.
It was also produced in China
Production of the RT model range was officially ended in 1985 (it was the fire brigade versions that lasted the longest) and by that time over 150,000 cars had been produced. Until the 1990s, however, the last specimens were being assembled from previously produced parts, and the original ones are very reliable, so the RT became the most widespread road truck in our country and was heavily exported.
And then there’s the Chinese Huanghe JN150 truck named after the Yellow River. It looks almost identical to our RT, but it is not a direct copy. Czechoslovak engineers built a truck factory in China in 1956 as part of a cooperative effort, and that’s how our liazek twins were born there from 1960. But their six-cylinder engines were from Shanghai and were modified marine propulsion units. In 1966, production there was interrupted due to the Cultural Revolution. It was restored only in the second half of the seventies and ran until 1985. Cars similar to the JN150 were also produced by other Chinese automakers.
The successor was the MT series (a modernized trambus, a temporary intermediate type that ended up being produced for over 20 years) with a new 100 series engine and Praga ten-speed gearbox. However, the firefighting variant was never derived from him. The Škoda 706 RTO bus with a lowered and extended frame was derived from RT trucks, and RTD flatbeds were then built on this frame. The annual production of all RT types was close to ten thousand pieces per year, the highest was 9,142 in 1968.
The RTHP version is very popular with volunteer fire departments who keep it running and are happy that there are still plenty of parts available. After all, the article was also made possible by volunteer firefighters from the village of Hůrky in the Rokycan region. Their congregation was founded in 1899 and a year later they had their first hand syringe. They bought the Škoda 706 RTHP manufactured in 1981 in 2007 from the choir from Holýšov. The car is actually still in its original condition, only with modernized equipment and a modern radio.