Throwing in the winter can present all sorts of challenges, but as I keep repeating on this site, it is important to throw the hammer year-round. The weight throw might look like the hammer throw, but nothing can replace the real thing. Throwing outside is the best option since you can get more feedback from your results, and I posted some tips for doing that last month. But it isn’t possible for everyone. In some places the winter is just too extreme to have a productive training session outside. Elsewhere, you are constrained by limited sunlight. If you work a normal job, or even a part-time job, it can be difficult to find daylight hours to go throwing (luckily our new facility this year has some lights since that was the major issue for me last season).
A decade ago I thought that throwing the hammer would be difficult to do inside, but since then I have found that it is easier than you might think. When I first visited Kamloops in 2005, we threw in a converted military bunker against three-foot wide strips of heavy rubber convey belts hanging from the ceiling. An old high jump mat was placed underneath to catch the falling implements. Without central heating, the facility would sometimes drop to -10º or -20º Celsius, but it allowed us to keep training when throwing outside was not an option. In between throwers we all huddled around a space heater to keep feeling in our hands. After a few years we broke most of the ceiling lights and eventually took out a portion of the concrete wall when a strip of rubber came down. While this helped provide more light, rumors that asbestos being used for insulation left us a little scared.
The Tournament Capital Centre, Kamloops’ new indoor track and training facility, opened in 2008 and was a big improvement. We moved from one of the worst to one of the best indoor facilities in the world. The new multi-million dollar center featured a room built specifically for indoor throwing and designed by former Kamloops coach Derek Evely. The construction was built on similar principles: rubber belts hung from the wall to absorb the impact and additional belts were attached to the ceiling to deflect throws towards the ground. The floor, except for a cement throwing circle, was also rubberized to allow it to take the impact of thousands of throws.
Between these two extremes are several options that can be implemented fairly easily. I’ve posted some photos of examples below (click to enlarge) and included a few things to consider.
The most important element of an indoor throwing facility is material you throw the hammer into. It has to be soft enough to take an impact, but strong enough to withstand constant abuse. The most common solution I’ve seen is to use netter similar to what is used on a hammer cage. Netting is easily available and fairly easy to hang. However, it can be quite expensive. In Seattle we used to be able to get old netting from fishermen, but that supply-chain no longer works. If you use netting, I have been told to use no less than 72-pound netting (96-pound is possible) with a 2-inch square pattern. I also find it helps longevity if you put a canvas tarp or second layer of net over the impact area as the friction from the wire and handle can slowly break down the net. A facility built by Kevin Becker in Illinois a few years ago uses only tarps and works very well (see a video here).
As I mentioned, Kamloops uses rubber conveyor belts. That option was used mostly because it was easy to come by in the community since the many local manufacturers had no need for broken belts. Rubber is very durable and works very well for small areas since, unlike lightweight nets, you do not need a lot of empty space behind for it to give way. But the downside of rubber is that it is also very heavy and can be difficult to secure to the ceiling. The rubber should be also two think to make sure that the hammer does not fly between two different pieces.
Also important is the landing area. A good landing solution will protect both your flooring and your hammers. Even with rubber floors, the facility in Kamloops uses an old high jump mat to provide an even softer landing area. Many times clubs and schools throw need to throw old mats after buying new ones, and donating it to throwers saves them the cost of taking it to the dump.
A high jump mat is actually thicker than is needed. In Europe I often see thicker gymnastics-type mats being used (you can see the thin mat used in Loughborough in this video).
Finding a good facility can be the most difficult part since space normally requires money. An indoor ring takes approximately the same imprint that an outdoor hammer cage takes. The obvious choice is to use some space near an indoor track or other dedicated athletics facility. An empty warehouse works well, but my friend Brian Richotte recently converted a squash court into a throwing room. As you can see, many options are available.