Types of Harnesses
 

This document outlines the advantages and disadvantages.

There are four varieties of harness: 3,4,5 and 6 point belts. The number of ‘points’ is the number of places they are anchored to the chassis or the roll-cage. 3-point harnesses have anchor points at either side of the seat and another behind it.

A 4-point harness has an additional anchor behind the seat (or on the roll-cage), a five-point harness has a further mounting at the base of the seat between the legs of the occupant and through a hole in the seat. A six-point belt has a further mounting point below the seat and between the legs. Five and six point belts are only normally used for racing because they are cumbersome to get in and out of and not practical for everyday use, although they increase security and help spread the force of an impact more evenly over the body in the event of a crash. Five and six point belts also help to decrease the risk of ‘submarining’ better than three or four point belts; ‘submarning’ is when the occupant slides underneath the belt.

There are three types of clip mechanism. First, the usual press-button release that is found in most cars. The second is an aircraft-style quick release that releases all the clips simultaneously allowing the occupant to be freed quickly. The third is only normally found in race-prepared cars because it is not as quick to apply as the others, this is called a latch and link release buckle and is not recommended for everyday use.

If you’re buying a harness to be used for racing then you’ll need to be sure that it meets the safety requirements of the event, the normal demand is that the belt is FIA approved. Most belts satisfy the FIA’s rules except some of the cheaper three and four point belts, although be careful when purchasing because there are a few expensive five or six point belts do not meet FIA safety requirements. Most belts that meet FIA requirements are clearly labelled as doing so and if you’re not sure walk away.

There are two thicknesses of belt, 50mm and 70mm, the thicker belt is better suited to motorsport because it spreads the weight over a greater area of skin and can be more comfortable but it is also more expensive.

Back to Top
 
 
Advantages
 

The are numerous benefits of fitting a harness but the best reason is the increase of driver and passenger safety. Harnesses help spread the force of an impact better than normal belts and are therefore less damaging to vital organs in the event of a crash. They’re also better at restraining an occupant during a rollover and help prevent sub-marining during a sudden stop. Harnesses are also better at reducing whiplash than the usual inertia belts because the head is held closer the head restraint (assuming it is properly adjusted.)

Driving pleasure is increased by holding the driver tighter in to the car and assists in making him or her part of the vehicle. It really does make driving more fun and they look a little special too.

Back to Top
 
 
Disadvantages
 

The biggest problem with harnesses is the practicality issue.

Unless you have a two-seat car then you’re going to lose the seats in the back because the straps of the harness are usually anchored to the mounting used for the back belts.Special seats can be found where the harnesses are anchored directly to them but these are expensive, rare, and have their own practicality problems. Another practicality difficulty is a consequence of how tightly a driver is held in to their seat, it is quite common not to be able to reach all the controls in a car, such as the radio or heater switches. If you’re happy driving whilst cold and in silence (or listening to your sweet Alfa engine) then this may not be as much of a problem.

 For the harness to be effective it must be tight and the fitting, therefore, differs for each occupant. If more than one person drives the car you may find yourself spending ten minutes adjusting the belt before you can safely drive, and unless you only have one friend its probably not a good idea to get a harness for the passenger seat.

 Harnesses are more uncomfortable for women, particularly those with large breasts. Also, many people do not like being held tightly in the seat and feel claustrophobic during a journey.

Back to Top
 
 
Fitting
 

There are two methods of fitting a harness to the car.

One method is bolting the eyelet holes of the harness directly to a seat-belt mounting using a simple bolt, nut and washer.

Another solution is screwing eyelet bolts in to the seat-belt mountings and using specially designed clips on the harness to clip through the eyelet. The advantage of the clip style harness is that it can be more easily removed or changed for another, the disadvantage is that it is not legal for road use because the law requires a seat belt to be permanently fitted.

Make sure you know which type of harness (fixed or clip) you are buying so you don’t get caught out at MOT time, however, if you keep your existing inertia belts then you could use the clip style harness legally. It is worth noting that eyelet type bolts can be used as normal bolts, you’ll just have the metal loop protruding.

Some harnesses, or versions of a particular model, are designed to attach to a roll-cage (as well as the chassis.) These harnesses have a loop of fabric that slides over the bar of the roll-cage running at shoulder height near the back of the seat.
It is not recommended you try creating mounting points yourself unless you are a qualified mechanic because it is illegal to do so

Back to Top
 
 
Conclusion
 

In conclusion, a harness can be an effective method of increasing passenger safety, although this comes at the cost of convenience.

Our Thanks to Graham Redway & Luke Anthony