Going through walls

For example fire fighters may need to get access to a burning building when all the obvious exits are blocked to rescue people trapped inside. Although a JCB may do the job, carrying one to the scene of every fire is hardly a practical solution. Additionally, Police may want to quickly apprehend suspects without warning them that they are coming or in this age of terrorism it might be necessary to be able to very quickly enter a building by an unexpected route to surprise terrorists and rescue hostages. Although, the SAS will do the job with explosives, this is more of an art than a science and often lacks any kind of finesse or accuracy. The military approach often involves causing maximum damage to shock and, if possible, kill the enemy. The Challenge Our challenge this month, is to come up with a best possible method of making a man sized hole in a wall or ceiling, or knocking down a stout door, in the shortest possible time and without causing any more damage than absolutely necessary. The device should be relatively portable and as simple as possible. Additionally, in this age of environmental concern it should be as ecologically friendly as possible, not start a fire, and not leave any noxious residues. The British developed and manufactured solution offered in the R & R section of our website solves the problem elegantly and at remarkably low cost without recourse to any kind of electronics. Once you see it, you may consider it obvious. If you can't guess it, the solution will be described fully in our November edition. See if you can come up with anything better. Solution The solution to our October challenge, to instantly knock a man sized hole in a wall while minimising damage and casualties may be solved by using compressed air to fire a plastic bottle of water at it. The technology is known as the "Wall Breaching System" or WBS, and has been developed and is manufactured by Cardiff military suppliers, BCB International. The WBS fires a standard 20.2 kg drinking water container. These are inexpensive and available in most parts of the world. The inertia of the water in the bottle carries it through the wall. When the bottle breaks, it leaves only water and few pieces of thin plastic. One of the beauties of the system is that it can be fired from very close range, perhaps only 3m away from the target, and should any innocent person be on the other side, they are not likely to be hurt unless they are immediately behind the target area. Launched at 200 psi, the water bottles are said to be able to knock a man sized hole through a double skinned concrete block wall. Safe maximum working pressure for the air reservoir is 1,000 psi. Maximum effective range is about 90m and the whole device weighs 159kg. The company now additionally offers a smaller calibre air cannon capable of firing ordinary plastic beverage bottles of water. Suggested applications range from combating piracy at sea to launching bundled ropes that can be attached to larger diameter mooring or towing lines. Range of this device is typically hundreds of metres, depending on firing pressure.