Jib self-propelled crawler crane RDK-250: specifications

2024 Author: Howard Calhoun | [email protected]. Last modified: 2023-12-17 10:16

A new brand is not always born from scratch. Sometimes it appears as a result of an agreement between producing countries, and then separated. Very often, she retains traits inherent in both parents. A striking example of such a solution is the Soviet-German production of construction cranes founded in the 70s of the last century.

For use on the territory of the Union, versions of the RDK-250 were produced. Specifications, pros and cons, as well as the history of the creation of this "real monster" among its fellows, we will consider in this review.

Model history

Before moving on to the history of the creation of 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 MKG-25 crane, created in the Ukrainian SSR. Its name was simply deciphered - a crane with a lifting capacity of 25 tons, on multi-roller caterpillar trucks. The first German crawler crane came out of the Zemag Zeitz in 1967.

This was the first model of the RDK series - RDK-25. The crane was reliable, unpretentious in maintenance, and most importantly, couldwork on almost any platform. The machine was powered either from its own power plant or from an external 380 V generator. It was practically a Soviet model - the Germans changed the crane movement system, putting several motors instead of one, each of which was responsible for certain actions.

Development stages

In 1972, the first model is discontinued. It is being replaced by an improved version of the RDK-250. The lifting capacity of the new crane remains the same, but the “0” in the name should indicate that this is a completely new development.

For the sake of fairness, it should be noted that only the power plant has become new, the rest of the blocks have migrated from the first modification. Customers accepted the crane, noting, however, that it does not meet the standards of rail transport adopted 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. The Germans mark this option with the index "1" (first) and recycle the crane operator's cab. This is how the RDK-250-2 model appears - this time the changes concern only the height of the driver's cab.

Capacity in numbers

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 machine entered the market, in which this figure was already 63 tons. The entire line of Germans was marked the same way:first the model name, then 2 digits - the carrying capacity, and the unchanged "0" at the end - improved. At the same time, not only versions for the Union, but also for the CMEA countries were noted in this way. In parallel with 250, the RDK-280 crane came out. From the name it is clear that he had a different load capacity, other motors (made in Czechoslovakia), and the calculation for other climatic conditions.

Modifications

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

Besides it, a crane was produced, which received an additional index "3" in the name. He boasted a more powerful and modern diesel engine, as well as some new developments. One of them was an improved power circuit, which had the ability to completely switch to one source. If electricity suddenly disappeared at the construction site, the crane switched to work from a diesel generator. The latter consisted of two parts, which made it possible to turn them off separately, without compromising performance.

Features of German developments

Unlike the Soviet prototype, German-assembled cranes could be used not only in the construction of buildings and structures. With a grab, the machine could be successfully used for loading and unloading. Thanks to a certain unification, the jib craneGerman-made could use most of the additional nozzles used for conventional machines of this class.

Sharing the load across multiple motors could change the crane's ability to travel. In addition to the main tasks, new developments could be used to move heavy loads.

Boom mechanism

Even after the development of the RDK-250-2 version, when moving over long distances, the boom had to be dismantled from the crane. But this need also had a downside - workers could lengthen the boom right on the site.

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 finger joints, it could be almost tripled. The maximum length could be 35.5 m. In addition, the Germans provided two options for the jib - a fixed rigid 5 m long or a movable-swivel one. The latter could have been extended.

Optional equipment

The possibility of extension allowed this jib crane to be used 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 - boom or tower, the main differences between which were in the upper end. But later, in addition to these two options, a third one appeared - a pile-driving mast, mounted on the cabin, like ordinary tower equipment. This immediately expanded the application of the crane - from the initial stages to the endconstruction. And the ability to lift the load to a height of more than 20 meters allows you to use it for the construction of structures of sufficient height.

Crane transportation

The same specifications state that the RDK is a mobile crane, however, like most construction equipment, its own travel speed is only 1.5 km / h. Outside the construction site, this is a good indicator, especially considering that he could move around with a load on the hook, but had to use either road or rail to transport him to a new place of work.

The movement was carried out in several stages:

• dismantling the boom, tower, masts;
• check-in on a low loader trawl (the case of transportation by road);
• shipping.

Then there was a reverse assembly at a new location.

For transportation by rail, it was most often carried by another crane and placed on an open platform.

Currently

The Germans completed the production of cranes in 1993. Nevertheless, it can still be seen on many high-rise buildings in Russia. Thanks to reliability, unpretentiousness, the ability to move with a load, the model is still in service. It should also be noted that RDK-250 spare parts can be found in any large specialized workshop.

You can replace metal inserts for the boom, rope, wheels or crawler assemblies, other parts of the crane. Despite the end of production, the choicecomponents allows you to use this version for a very long time.

Separate mention can be made of the possibility of unification, thanks to which the crane can use almost any device designed for other models. And also the possibility of using attachments, turning it into a pile driver or even a drilling rig.

Features

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

• width - 3225;
• length - 6275;
• height - 3350.

All data without boom, in transport position.

Load characteristics for standard operation on boom with inserts:

• lift height (maximum) - 45 m;
• lowering depth - 6 m;
• carrying capacity - 25 t;
• maximum and minimum reach - 22 and 4 m respectively;
• load lifting speed - 7.5 m/min,
• lowering - 15, 5 (it should be noted that two motors could work for lowering).
• speed of movement with a load on the hook - 1 km/h, without load - 1.5 km/h.

We also include here that the self-propelled crane had separate travel and rotation mechanisms, as a result of which the upper part with the cab was able to make a complete rotation around the axis in two minutes.

It should also be noted that the caterpillar base made it possible to carry outwork even on an inclined plane:

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

Since the turning part of the crane almost completely repeats the one on pneumatic wheeled vehicles, we will dwell in more detail on the undercarriage, the lower part. The movement of the crane is carried out with the help of a pair of engines, on the shafts of which the drive wheels of the crawler trucks are located. Between the upper, rotary and lower parts there are current collectors connecting all electrical circuits. An output cable with a plug sleeve is provided for power supply from an external power source. In addition to the crane operator's seat, one more person can sit in the cab. In front of the lower frame there is a fenced trolley for repairing the motors of the travel mechanism. Access to the rest of the motors and maintenance of the electrical system is through the covers on the bottom.

Conclusion

Created as a result of Soviet-German cooperation, the RDK-250 crane became a real godsend for the mass construction of the early to mid-1970s. The presence and possibility of using additional equipment more than paid for the cost and size of such a machine. Moreover, the crane could not be bought. Many large construction companies were willing to rent it to you with their own MOT.