Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations SSS148 on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Pile Driving? 3

Status
Not open for further replies.

abusementpark

Structural
Dec 23, 2007
1,086
I was just wondering what the most widely used hammer for pile driving is? Diesel? Hydraulic? Vibratory? Or does it depend on the soil?
 
Replies continue below

Recommended for you

Depends on driving conditions. Diesels are poular because they are light, do not require a hose or power unit. However they do not run well in cold weather or in softground. The energy delivered is not as easy to compute as with a hydraulic or air hammer. A hydraulic can deliver high energy due to log drop and or down pressure on the ram(double acting). The amount of energy delivered during driving can be adjusted and some units can give detailed information on enrgy delivered. The disadvantage is that they can be very heavy, need a hydraulic unit with hoses that must be moved with the crane. They are also very expensive. Air hammers are Old School, but still very popular. They can be single acting(air raises hammer which falls under gravity or doble acting, where air increases driving force. They are typically heavier than the diesel and the same or somewhat lighter than comparable hydralics.
They need an air line and a compressor which must be moved with the crane.
The Vulcan 1 is kind of a standard hammer (If I had to pick one) It has a 5,00 pound ram and a drop of three feet. It operates at 60 blows a minute. So if you count 15 blows in 15 seconds, you know the hammer is workig properly. It has few moving parts and can suffer abuse associated with this work and requires little maintance.
 
Aw Shucks.
Thank you.
I would like to thank you for your awesome website. I link to it frequently for all kinds of stuff you can't find anywhere else.
 
Nice post, DRC1.

Are there any places where the diesels are restricted due to environmental concerns??
 
Thank you. I have not heard of any (except for noise restrictions, which are a problem for all hammers). The amount of fuel burned is small,esp. in comparison to the crane holding the hammer, so I don't think there would be an enviornmental concern.
 
DRC1, thanks much for the recommend for the Vulcan #1. (Ram weight = 5,000 lbs.) Do you realise this this product line is 110 years old? And some of the hammers still in use date from the turn of the last century? Their simplicity is a major reason why they're still in the field. Pile hammers spend a lot of time sitting in a yard (and in the weather) between jobs, and an air hammer will endure that better than any other kind.

One thing I would mention is that, although the blow rate for an air/steam hammer is reasonably consistent, it isn't as absolute a way of correlating an energy as a single-acting diesel hammer. In other words, you can't do a "Saximeter" type of correlation for an A/S hammer as you can for a S/A diesel. The best way to insure the energy output of an A/S hammer to be acceptable is to make sure it's in good running condition (especially lubricated) and getting a full stroke.

With differential acting hammers, the pile rebound complicates things considerably re the blow rate. Back around the time of the last depression (terminology deliberate,) Vulcan introduced its differential acting hammers with a correlation between blow rate and energy. Needless to say, Vulcan was forced to beat a hasty retreat on that one, and I still get the occasional inquiry about that!

Information on Vulcan hammers can be found at


One thing about diesels and the environment concerns their use overwater and dripping oil and fuel. But diesels can be modified to use environmentally friendlier fuels (biodiesel, etc.) to mitigate these problems. Anyone who's been around diesels knows that they are "dirty" hammers by nature, but the manufacturers have done a reasonable job addressing the issues surrounding them.



 
Status
Not open for further replies.

Part and Inventory Search

Sponsor