Piling and vibratory equipment specialist Pilequip recently announced it will be representing the Tünkers range of shock absorbers. David Hopkins, Pilequip’s national sales manager, provides some background to the Tünkers product and explains why the crane sector should embrace the product.
Tünkers is a German manufacturer of specialised industrial equipment. Its range includes piling equipment and vibratory hammers for sheet piling.
“Unlike the products we sell, which have a series of rubber absorbers above the vibrating unit, Tünkers’ own piling equipment doesn’t have any, so they developed a range of auxiliary rubber shock absorbers for their own vibratory equipment, which, when used in combination with the latest vibratory technology, from manufacturers such as Dieseko, create a very effective damping mechanism,” said Hopkins.
“There are, typically, two types of vibratory hammers. There’s a static-moment vibratory hammer and a variable moment hammer. The biggest issue with the static-moment hammers is, when you turn them on, they spin through the low frequency until they get to their peak frequency. When it’s moving through the low frequency, it starts to shake. It’s a bit like an off-balanced front-load washing machine. When it’s a little bit off balance and starts to spin slow, it starts to jump around, but once it gets up quite fast, it quietens down.
“When it starts and stops, we get those really big shock load vibrations going up into the crane. It’s not good for the computers. It’s not good for any componentry on the crane itself, and some of the crane OEMs state in their literature that they need to have a shock absorber when using vibratory equipment.
“It’s not just the starting and stopping of the equipment. There are heavy vibrations even at the peak frequency, particularly if you’re pulling up on the vibratory hammer. You’re still getting quite a lot of vibration going up through the crane line and into the crane. We found the Tünkers shock absorbers eliminate up to 75 per cent of that shock load vibration and up to 93 per cent of peak frequency vibration.
Pilequip tested the shock absorbers in its yard on a 75t capacity crawler. It engaged VMS Australia, a specialist vibration monitoring company, to measure the vibration. VMS put up four different measuring points on the crane: above the hook, at the top of the jib, midway on the boom, and in the cab.
“We tested the shock absorbers on a static movement hammer, an ICE 32NF, and we also tested a variable moment hammer, a PVE 28VM. A variable moment hammer doesn’t have that start and stop shock as I mentioned earlier. So, essentially, it doesn’t start vibrating until the frequency is high. But, as soon as you start pulling on that vibrator, you get that same peak frequency vibration going up through the crane. That doesn’t change whether it’s variable moment or a normal frequency hammer.
“As I have said, the Tünkers rubber shock absorbers reduced the vibration by up to 93 per cent. Obviously, there are huge benefits for crane companies considering this product. I’ve spoken to customers operating cranes and computer systems can’t handle the vibrations. It keeps resetting or it keeps getting errors.
“Obviously, the absorbers will help prevent general wear and tear on the crane. I’ve spoken to customers who have got a crane down because they started a big static-moment hammer, the ropes were jumping around all over the place, and this caused damage to a point where they couldn’t operate it anymore, they had to fix it,” said Hopkins.
Anyone that owns a crane and is planning to put a vibratory hammer on it, utilising the Tünkers rubber shock absorbers seems to be a fairly straight forward business decision to make says Hopkins.
“They’re relatively inexpensive to either rent or buy, when compared to the cost of a crane or fixing the damage vibration has caused your crane. It’s the unknown damage that needs to be considered.
“I don’t know if there’s any studies on the impact of long-term use of a vibratory hammer on your crane, but you can only assume that it would be significantly less when we’re talking about the vibration reduction that these shock absorbers can achieve,” he said.
The Tünkers rubber shock absorbers are also relatively low maintenance. The wire links in between the shock absorber seldom do they need replacing if they are well looked after and and inspected regularly.
“You can expect years of service life from a Tünkers rubber shock absorber, with minimal maintenance, they are virtually maintenance free,” said Hopkins.
The Tünkers rubber shock absorber range includes five different types of shock absorber ranging from 12t of line pull up to 80t of line pull. Pilequip is stocking three types, from 25t to 80t, these being the SD-70 with 25t line pull, the SD-130 with 50t of line pull and the SD-185, which has 80t.
Pilequip has been providing products to the piling industry, in Australia for over 30 years. Over this period there have been a number of owners. Two years ago, Pilequip was bought by Dieseko, a Dutch company that manufactures vibratory hammers, piling rigs, and impact hammers.
“Being a member of the Dieseko family is the next stage for our business. There is a vast amount of product in the piling industry that has been sold and serviced by Pilequip Australia, and that’s not just vibratory hammers and impact hammers.
“There are very few piling companies out there that have had no interactions or purchases from us and we hope it the be the same with the crane industry with the Tünkers range of rubber shock absorbers,” said Hopkins.