Even though the original concept of a steam hammer dates back to James Watt in 1784 it was not until the 1840s that the first working steam hammer was produced. The first working machine was built by François Bourdon in France and led to a very heated dispute with British inventor James Nasmyth who claimed that his original designs had been copied. In the 1800s there were no arbitration panels, no patent protections and the world of inventions was as brutal as the force of a steam hammer itself!
What is a steam hammer?
While you will see very few steel hammers in the world today they were commonplace during the industrial revolution. The most common types of steam hammer were the single-acting and double-acting machines which depended upon steam pressure to rise and lower the steel hammer “ram”. The mechanics behind a single-acting steel hammer are relatively straightforward:
- Steam is injected into the lower part of the cylinder creating pressure
- This pressure causes the cylinder to rise (and the connected ram)
- The steam is the released
- The release creates a vacuum which draws the cylinder down
- Gravity adds to the downward pressure
A double-acting steel hammer works in exactly the same manner as a single-acting device except additional steam is injected at the top of the cylinder cycle. This allows both the force of gravity, using the weight of the steam hammer ram, and the pressure created by the additional steam to create an even more powerful downward movement.
Uses of a steam hammer
The initial uses of a steam hammer revolved around dies over which metal materials were placed with the intention of shaping them into whatever dimensions were required (forging). In some steam hammers there were two dies, one at the bottom of the device and one on the end of the steam hammer ram. As the cylinder was pushed to the top of its cycle and released, by the injection and release of steam, it created an immense force which allowed the metal to be forged blow by blow. As you can guess, instances where metal needed to be shaped and forged are numerous today but there were also many back in the 1800s and the 1900s.
The steel hammer was also known as a drop hammer and was also very useful when pile driving posts and rods into the ground. In a similar fashion to the machines used with metal and dies, the downward force was used to push structures and materials into the ground. This not only saved hours of manual labour but also ensured that the structures were pushed as far into the ground as possible to give more strength to the overall structure – vital foundations.
Size and force of a steam hammer
The weight of the ram attached to the cylinder of a steam hammer could range from 225 kg up to 22,500 kg. We can only imagine the enormous weight this could exert using gravity alone let alone the two steam injection processes. The constant pounding of the steel hammer would literally shake the foundations of the building hence the reason why the lower anvil was often connected to a wooden support. The wood material was able to absorb a portion of the downforce created which was reverberated over a wider space. In the early days the steel hammer rams were made of numerous components as the extreme pressure and wear and tear would regularly disable the machine. The decision to make the steel hammer rams of individual components meant that each failed part could be individually replaced – leading to great time and cost savings. As time went by engineers discovered more durable and toughened materials which prompted the production of one-piece steam hammer rams.
The downforce created by the steel hammer ram was dependent upon not only the size and the weight of the ram itself but also the level of steam injection and the pressure created. This allowed later improved versions of industrial steel hammers to offer more control to the user hence greater options in the workplace.
Steam hammers quietly phased out
There is no doubt that steam hammers, although a relatively simple concept, played a major role in the industrial revolution. Eventually as technology progressed they were displaced by hydraulic and mechanical presses which gave users more control and offered greater reliability and durability. Museums around the world house an array of steam hammers from the early days, right through to the later developed models. They look cumbersome, they look inflexible but ask any mechanical engineer about their contribution to the industrial revolution and you may be there for a while!