Self-propelled crawler crane RDK-250: technical characteristics

A new brand is not always born from scratch. Sometimes it appears as a result of a contract between producer countries, and then it separates. Very often she has the features inherent in both parents. A vivid example of such a solution is the Soviet-German production of construction cranes, founded in the 1970s .

For use on the territory of the Union, versions RDK-250 were issued. Technical characteristics, pluses and minuses, as well as the history of creating this "real monster" among their fellow men, we will consider in this review.

History of the model

Before turning to the history of creating the described crane, it is worth noting one interesting fact. It was created by the Germans for use on the territory of the Union. But the prototype of the German model was the crane ICG-25, created in the Ukrainian SSR. Its name was simply deciphered - a crane with a carrying capacity of 25 tons, on multitrack caterpillar trolleys. The first German crane on the caterpillar track came out of the gate of Zemag Zeitz in 1967.

This was the first model of the RDK-RDK-25 series. The crane was reliable, unpretentious in maintenance, and most importantly, it could work practically on any site. The machine was powered either from its own power plant or from an external 380 V generator. In practice it was a Soviet model - the Germans changed the crane's traveling system, placing several engines instead of one, each of which was responsible for certain actions.

Stages of development

In 1972, the first model is removed from production. To replace it, an improved version of RDK-250 appears. The carrying capacity of the new crane remains at the same level, but "0" in the name should indicate that this is a fundamentally new development.

For the sake of justice, it should be noted that only the power plant became new, the rest of the blocks were removed from the first modification. Customers accepted the crane, noting, however, that it does not go according to the standards of rail transportation accepted in the Union. For transportation it is necessary to remove not only the boom, but also the cabin, otherwise the height of the load goes beyond the limits of the norms. The Germans mark this option with the index "1" (first) and process the cabin of the crane operator. So the model RDK-250-2 appears - this time the changes concern only the driver's cab height.

Carrying capacity in figures

It should be noted that cooperation with the Germans continued until the collapse of the Union. In 1983, crawler cranes RDK-400 appeared. As the name implies - the carrying capacity of the model was 40 tons. This crane was produced for 7 years, and in 1990 a car entered the market, which already had 63 tons. The whole line of Germans was marked in the same way: first the name of the model, then 2 digits - the carrying capacity, and the constant "0" at the end - improved. At the same time, not only the versions for the Union, but also for the CMEA countries were noted. In parallel with the 250 came out the crane RDK-280. From the title it is clear that he had a different carrying capacity, other motors (the production of Czechoslovakia), and calculation for other climatic conditions.

Modifications

For the Soviet Union was produced about 15 thousand cranes with a carrying capacity of 25 tons. In addition to the already mentioned versions 1 and 2, the Germans also released two more modifications. For work in the Far North the version of RDK-250-4 was intended. It differed from all previous models of insulated cabin, the ability to work at -50 degrees, enhanced protection, and other details.

In addition to it, a crane was produced, which received an additional index "3" in the name. He could boast of a more powerful and modern diesel engine, as well as some new developments. One of them was the improved power scheme, which had the ability to fully switch to one source. If electricity suddenly disappeared on the construction site - the crane moved to work from a diesel generator. The latter consisted of two parts, which made it possible to disconnect them separately, without prejudice to the work.

Features of German developments

Unlike the Soviet prototype, the cranes of the German assembly could be used not only for the construction of buildings and structures. With the grapple, the machine could be successfully used for loading and unloading operations. Due to a certain unification, a German-made boom crane could use most of the extra attachments used for conventional cars of this class.

Separation of the load on several motors could change the mobility of the crane. In addition to the main tasks, new developments could be used to move heavy loads.

Arrow mechanism

Even after the development of the RDK-250-2 version, when moving over large distances from the crane, it was necessary to dismantle the boom. But this need also got a downside - workers directly on the site could extend the boom.

In the basic version, it had a length of 12 meters. But with the help of additional inserts, which, like the arrow itself, were attached to the finger joints, it could be increased almost threefold. The maximum length could be 35.5 m. In addition, the Germans provided two options for the jib-fixed rigid 5 m long or movable-swivel. The latter could also be elongated.

Optional equipment

The possibility of lengthening made it possible to use this jib crane not only for its intended purpose - for lifting and moving cargo. According to the developer's specifications, the basic equipment could be of two types - an arrow or a tower, the main differences between which were at the top end. But later, in addition to these two options, there was a third - pile-driving mast, mounted on the cockpit, like a conventional tower equipment. This immediately expanded the application of the crane - from the initial stages to the completion of construction. And the ability to lift cargo to a height of more than 20 meters allows it to be used to build structures of sufficient height.

Crane transportation

The same specifications say that RDK is a self-propelled crane, however, like most construction equipment, its own speed of movement is only 1.5 km / h. For the limits of the construction site, this can be called a good indicator, especially if you consider that he could move with cargo on a hook, but when transporting it to a new job, he had to use either auto or railway transport.

The movement was carried out in several stages:

• Dismantling of arrows, towers, masts;
• Arrival by their own motion on the low-frame trawl (case of carriage by road);
• shipping.

Next was the reverse assembly in a new location.

For transportation by rail, it is most often with the help of another crane, it was transferred and put on an open platform.

Currently

The Germans finished the production of cranes in 1993. Nevertheless, many high-rise buildings in Russia can still see it. Due to reliability, unpretentiousness, the possibility of moving with a load, the model is still in operation. Also it should be noted that spare parts RDK-250 can be found in any large specialized workshop.

You can replace the metal inserts for the boom, rope, wheels or crawler trolleys in the assembly, other parts of the crane. Despite the end of production, the choice of components allows this version to be used for a very long time.

Separately mention the possibility of unification, thanks to which, the crane can use almost any device developed for other models. As well as the possibility of using attachments, turning it into a pile for driving a pile or even a drilling rig.

Characteristics

In this section we will include the other parameters of the RDK-250 that remained before in the shadow. Technical characteristics are presented in the form of several lists. Let's start with external parameters (all in millimeters):

• Width - 3225;
• Length - 6275;
• Height - 3350.

All data are indicated without regard to the boom, in the transported position.

Cargo characteristics for standard work on the boom with inserts:

• Lifting height (maximum) - 45 m;
• Depth of lowering - 6 m;
• Load-carrying capacity - 25 t;
• The maximum and minimum departures are 22 and 4 m respectively;
• The lifting speed of the load is 7.5 m / min,
• Lowering - 15.5 (it should be noted that two motors could work on the lowering).
• Speed of movement with cargo on the hook - 1 km / h, without cargo - 1.5 km / h.

Here we also refer that the self-propelled crane had separated mechanisms of movement and turning, as a result of which the upper part with the cab was able to do a complete revolution around the axis in two minutes.

Also it should be noted that the caterpillar base allowed to carry out work even on an inclined plane:

• In the arrow design - 3 degrees with load and up to 15 without;
• In the tower version - 2 degrees with a length of this to 27 meters, over - no more than one.

Since the turning part of the crane almost completely repeats this on pneumatic-wheeled vehicles, we will dwell in more detail on the running, lower part. The movement of the crane is carried out by means of a pair of engines, on the shafts of which the driving wheels of caterpillar carriages are located. Between the upper, rotary and lower parts are laid current collectors connecting all electrical circuits. For power supply from an external power source, an output cable with a plug sleeve is provided. In addition to the place of the crane operator, another person can sit in the cockpit. In the front part of the lower frame there is a fenced trolley for repairing the engines of the movement mechanism. Access to the rest of the engines and maintenance of the power supply system is done through the covers at the bottom.

Conclusion

The crane RDK-250, created as a result of Soviet-German cooperation, was a real find for the mass construction of the early-mid-1970s. The availability and the possibility of using additional equipment more than paid off the cost and dimensions of such a machine. Moreover, the crane could and did not buy. Many large construction companies agreed with their own maintenance to provide you with it for rent.