Demolition of a bridge in Leeuwarden
Hydraram demolition tools make short work of the “Drachtsterbrug” in Leeuwarden.
Beginning of September, Van der Wal demolition company from Joure started the demolition of the old Drachtsterbrug bridge in Leeuwarden. To complete the great project, this Frisian demolition contractor needs a lot of equipment. The demolition of the bridge deck, the pillars and the associated landings requires heavy machinery. In addition, there is a considerable amount of time pressure on the project. The old bridge and viaducts can be removed once the new aqueduct is ready. Van der Wal joined up with Peter Wassenaar of Hydraram in Surhuisterveen to supply suitable demolition tools. Along with many Hydraram accessories, Hydraram offers a diverse repertoire of demolition tools. That is also the strength of the Frisian company as well. Customers can temporarily rent the tools, which helps them get an impression of their abilities. The tools available for renting may also be purchased!
Fittings can also be rented for a project for a short period of time. Hydraram has temporarily rented a FX-460 Pro hydraulic hammer, MK-20 multiprocessor, HCC-85V concrete crusher and HRP-72V rotating pulverizer to Van der Wal. The FX-460 Pro weighs 3.2 tons and is deployed on their own Doosan DX380 excavator. The hammer is suitable for machines in the weight range of 34 to 50 tons and requires between 190 and 280 bar of working pressure. This Hydraram tool is equipped with automatic grease lubrication to make sure the chisel bushes are properly lubricated and unnecessary wear is prevented. This gives the hammer the right amount of grease, which saves on maintenance costs. Of course, the operator must keep an eye on the grease container to make sure it’s not empty. A HFP-25V fixed pulverizer machine is used for the crushing of the bridge and viaducts. It weighs 2,450 kg and demands 350 liters of oil per minute at a working pressure of 350 bar. The crusher is suitable for machines between 25 and 32 tons and has a jaw opening of 852 mm. It has knives on the inside of the jaw to cut concrete iron. The maximum power at full opening is 85 tonnes.
A major advantage of fixed pulverizers is that they are fitted with two replaceable teeth on the fixed jaw. This allows the concrete to split apart and thus remove more concrete iron between the debris, which causes more iron yield. Because of the replaceable teeth, maintenance costs are low and the rest stops are kept to a minimum. There is no need for welding while attaching and little to no heat has to be introduced. This also improves the life of the pulverizer attachment. The HFP-25V is also used by their own crane, as well as the the MK-20 multiprocessor, which is fitted with a pulverizer jaw. Other types of jaws are available with the MK multiprocessors- for example a combi, demolition, steel cutter, tankshear or universal jaw. The base yoke weighs 1.465 kg and the crush force is 1.010 kg. Before cutting, the multiprocessor requires between 200 and 300 liters of oil per minute and this at a working pressure of 310 bar. The rotation requires 10 liters per minute and the maximum operating pressure is then 140 bar.
A major advantage of the MK-20 is that it is possible to perform all common demolition work with only one piece of equipment. Depending on the nature of the demolition project, you can choose which jaw you’d like to use. Most popular types are the combi, pulverizer and steel cutter jaw.
The Hydraram HCC-85V concrete crusher is used for the large joints of the bridge and viaducts. The crusher attachment is fitted to the Cat 385C which was also hired for this task. The crusher weighs approximately 8.5 tons and has a maximum opening of 1,830 mm. The maximum cutting force at the tip of the teeth is no less than 185 tons! On the inside, the concrete scissors have cutters to cut concrete steel. Those cutters contain the cutting power of 720 tons. The HCC-85V is a great size for the 90-toner. Companies often want heavier scissors when a larger jaw opening is needed, even if they are too heavy for their excavator. This way not much work can be done and the machine can start to sway. This is bad for both the bucket cylinder and the excavator arm. The concrete crusher also has the capacity to pick up cut pieces of concrete and put them aside. The usual priority is to cut and lower structures as quickly as possible. In order to be able to work further, the crane must be able to put something aside, since the concrete has not been crushed yet. The project of `Drachtsterbrug` is no different in this scenario. The opening and closing of the big concrete crushers requires around 3.9 seconds. A very large Hydraram HRP-72V rotating pulverizer is used for much of the crushing work as well. The heavy concrete slats, deck and pillars contain quite a bit of reinforcement steel. Cutting with the large concrete crusher, a big portion of debris descends and should be cleaned immediately to finish the demolition process.
The use of crushers is requested to limit noise for the nearby inhabitants. The large Hydraram HCC-85C concrete crusher is an excellent choice in this case. Even the HRP-72V model can do the job well. It has a substantially large opening for a crusher in its weight class. The teeth are also placed in such a way - especially those on the front of the movable jaw - that the concrete is tightly clamped. This allows the crusher to work as a "scissor". The HRP-72V has a weight of 7.250 kg and is suitable for 68 to 85 ton excavators. It fits the Cat 374D perfectly. The crusher requires between 450 and 600 liters per minute for opening and closing of the jaw and a working pressure of 340 bar. Rotation requires 30 liters per minute and a working pressure of 140 bar. The maximum jaw opening measures 1.320 mm and the cutting force is 180 ton. The width of the crush is 790 mm. For this crusher, the manufacturer chooses the knives on the inside as well. Opening the crusher requires 3 seconds, and closing 3.7 seconds time. With the help of large demolition machines, Van der Wal workers successfully completed the project!