This is an M&R ribbon-style...
This is an M&R ribbon-style window net on a flat steel bar with a lever latch. Some sanctioning organizations require the lever latch. Remember this is mock-up for demon- stration purposes. All mountings on a race car should be fully welded. The SFI tag is always nice to see on any piece of safety equipment.
Window nets have been used in Stock cars for some time now. I guess I first used one 20-odd years ago. At the same time, I was putting some bars in front of the steering wheel. I'm as macho as any racer when I get in a race car. I figure I can be responsible for what I do to myself. But my attitude changes when I think of what could happen that I have no control over. It only took one picture of a race car upside-down with the driver's hand trapped under the roof to convince me to take some precautions.
After a number of years racing with a window net, I became aware of the effects of side impacts. A side impact can severely stretch a driver's head and neck to the side. When belts and a seat with rib support restrain the body, the head is left to flop around on its own. When I got a Sprint car, I did like everyone else. I put a head net on the right side of the cage. In the next Stock car, I decided to use a Sprint car head net on each side of the driver. When properly placed, the head nets contain the side movement of the head, not allowing it to reach the window net, thus reducing the neck stretch.
The window net does more than keep my hands in the car; it keeps undesirable objects out of the car. For this reason, net mounting brackets should be substantial.
I don't believe the 3/8-inch steel rods I used years ago to mount string-type window nets are strong enough. To keep my hands in, yes. To keep something else out, no. Although string nets are still sold, I can only recommend the ribbon or mesh nets. The ribbon is the stronger of the two. Some drivers think a ribbon net hinders visibility. For these, the mesh net can be used. I have never had a visibility problem with the ribbon net, and I don't have any problem seeing through a picket fence either.
There are some variations of net mounting hardware. Most manufacturers can supply several types. One of the more common ways is to use a 1/2-inch outside diameter by 0.065 wall thickness steel tube for the lower mount. The mounts for the tube are usually made from 0.095x1-inch-wide steel welded to the top door bar. A hole in each allows the tubing to slide through. The tube is then cross-drilled for cotter pins on each end.
Some of the hardware: 1/2-inch...
Some of the hardware: 1/2-inch od x 0.065 wall steel tubing is used for many window net mountings. A seatbelt buckle (top) is welded to the tube. The plate above is welded to the rollcage. The bracket on the left welds to the cage also; it lets the tube slide into position to be latched. Another type of lower mounting (bottom) is this weld-in clevis arrangement from Stroud Safety. from Stroud Safety.
Stroud Safety makes another variation on lower mount bars. A pair of clevises is welded to each end of the lower tube. These clevises are then bolted to metal brackets, which are welded to the door bar.
The top attachment mountings are usually seen in two types: the lever latch and the seatbelt buckle latch. Both seem to work well. I have used the seatbelt buckle latch for years with no problems. These usually have a round steel rod welded to the buckle. The lever latch-type is a slightly smaller version of that often used on a driver's lap belt. Many times, the lever latch-type is welded to a 3/16x1-inch flat bar. Some tracks and sanctioning bodies require a specific type latch. This is so the safety crew always knows what to look for in an emergency. Check your track rules before installing net latches.
Head nets are not new, but they are not seen as often as they could be. The first head nets I saw were used only on the right side on Sprint cars. They were not mounted close to the driver's head but rather on the right-side cage bars.
I don't mean to imply that I originated the idea of dual close-fitting head nets on Stock cars. I believe others were most likely doing the same thing at the same time, although I hadn't seen them. I do know that I began to give it some thought around 1995. It was a developmental thing. As late as 1999, when I built an I-Stock, the head nets were mounted high in front. Later I realized that in an angled impact, a driver's head could come forward and then return outside the net. Since then, I have made the front head net mounts at about doorsill level. This will keep a driver's head somewhat centered over his body and within the nets.