1.4. Single Acting Steam Hammer

Next is your single acting steam hammer, so this is an improvement over the drop hammer. As a name indicates steam hammer, so it means you are going to use a steam energy, you can either go for steam energy or you can go for compressed air also. So accordingly, you may need a steam boiler or air compressor for this method.

The single acting steam hammer is an upgrade from the traditional drop hammer. Unlike the drop hammer which relies solely on gravity, this hammer utilizes steam or compressed air to lift the hammer. This advancement requires additional equipment like a steam boiler or an air compressor to provide the necessary pressurized steam or air.

Think of the single acting steam hammer like a pneumatic jack used to lift a car. The pneumatic jack uses compressed air to push the jack up, making it easier than lifting the car manually. Similarly, the steam hammer uses steam pressure to lift its hammer for driving piles into the ground.

The name says single acting, that means you are going to use the steam energy only in the upward stroke. That means when you are lifting the hammer that is called as a upward stroke, only during the upward stroke I make use of the steam energy.

In a single acting steam hammer, steam energy is only used during the upward movement of the hammer. This means that when lifting the hammer, steam is allowed into the cylinder, causing the hammer to rise. In the downward motion, the hammer simply falls back down under the influence of gravity.

Imagine pumping a bicycle pump. When you pull the handle up, you’re creating a vacuum that helps lift the pump’s inner tube. When you push down, the tube comes back down easily without the need for extra energy. Similarly, in the steam hammer, steam is used to assist the upward movement only, while gravity takes over during the fall.

So, to complete an upward stroke what you are supposed to do is allow the air entry into the chamber. Once the air enters into the chamber, you can say as the air starts filling the chamber, your hammer will be raised up due to the air pressure.

The operation begins by allowing steam or air into a specific chamber of the hammer. As the steam fills this chamber, it generates pressure which pushes the hammer upward. This upward movement is essential as it prepares the hammer for the impact when it drops.

Think of how a syringe works. When you pull back the plunger, air enters the chamber, creating a space for liquid. Similarly, filling the chamber with steam prepares the hammer to lift, just like the plunger prepares to draw liquid when pulled back.

Now let us see how the downward stroke is done. Now what you do is you control the lever in such a way that the air inlet is shut off, you close the air inlet and all the air from the cylinder will be expelled out of the exhaust valve.

To execute the downward stroke, the operator closes the air inlet, which stops additional air from entering the chamber. Then, by opening the exhaust valve, the pressure in the chamber is released, allowing the hammer to drop freely due to gravity.

Imagine a balloon filled with air. If you pinch the end to stop letting air out, the balloon can stay inflated. But as soon as you let go, the air rushes out and the balloon collapses. In the same way, closing the inlet for the steam hammer allows it to drop without resistance.

So, when you compare the productivity of your single acting hammer with the drop hammer... But your single acting hammer has a better productivity, it can go of a 1 blow per second.

When comparing productivity, the single acting steam hammer is significantly more efficient than the drop hammer. The drop hammer can produce only 4 to 8 blows per minute, while the single acting steam hammer can achieve up to 60 blows per minute. This improved efficiency makes the single acting hammer preferable for projects with tight deadlines.

Consider the difference between hand drilling and using a power drill. Hand drilling takes longer, only making a few holes per minute, while a power drill can create many holes in the same time frame. The single acting hammer functions like the power drill, providing faster results.

As I told you the basic rule is, select a hammer having a weight approximately equal to that of the pile.

A fundamental guideline for selecting a single acting steam hammer is that its weight should ideally be equal to that of the pile being driven. This ensures effective energy transfer during the impact. If a hammer of equal weight is unavailable, it should not be less than one-third of the pile's weight, and the drop height should be limited to 4 feet for concrete piles to avoid damage.

It is similar to using the right size of a nail when hanging a picture. If the nail is too small, it won't hold the weight of the picture and may bend or break. Similarly, using a hammer of adequate weight ensures it can effectively drive the pile without damaging it.

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