The Seats and Seat Belts
Proper adjustment of the car seat is fundamental to effective use of the controls. The seat along with the seat belt and headrest is critical to safety.
There are two types of seat, bench and bucket. Seating is normally set facing forward as this gives the greatest protection in the event of the most common accidents, front or rear end collisions.
Side facing seats tend to be used when there is a dual purpose which includes load carrying. The bench seat which extends the width of the vehicle has to a large extent been replaced by the bucket seat.
Modern back seats tend to have bucket style mouldings along with individual seat belts. There are a number of reasons for this:
- A bucket seat is safer as it tends to mould to the body.
- The moulding in conjunction with the seat belt means a much greater survival chance in the event of a collision.
- By regulating people to individual seats this helps to prevent overcrowding of the passenger compartment.
- Separating the driver from the passenger means greater control for the driver.
The seat itself has been ergonomically shaped and firmly sprung to give support in both general driving and collisions. It should be positioned to give free and easy access to both the foot and hand controls. The back of the seat should be reasonably upright to ensure proper support in the event of a collision.
If the seat angle is too far back there is a risk of submarining. This is when in a collision you slide forward under the seat belt risking serious injury.
The purpose of the headrest is to stop your head rotating backwards over the back of the seat. The injury most commonly caused in this way is called whiplash.
In order to stop this happening the headrest needs to be correctly adjusted. The back of your head should be as close to the headrest as possible. To do this ensure that the back of the seat is reasonably upright consistent with free and easy access to the foot and hand controls. The height of the headrest should be at least that of the center of gravity of your head or higher.
The pointy bit at the back of your head (your occipital protuberance) is roughly in line with the top of your ear or the eye.
The Seat Belt.
Part of your car’s passive safety system. It is designed to contain you within your seat in the event of a collision.
In a collision anyone or thing that is not restrained will be thrown forward at the speed the vehicle was doing at the time of the collision. So if you hit a stationary vehicle at 30 mph anything or anyone not restrained will hit what is in front of them at 30 mph.
For you the driver this will be hitting the steering column. And for passengers in the back this will be them hitting you at whatever speed you are doing at the time. This will be made worse by the fact by its very nature the collision will be unexpected or very little warning.
Modern vehicles use a 3 point lap and diagonal system. This means the seat belts are designed to work upon the bony parts of your body. Thereby protecting the soft squishy bits like your internal organs!
The lap should be across your pelvis and the diagonal across the chest and shoulder. If the belt is across soft tissue such as the throat or abdomen these organs will be subject to the force of the collision.
The belt should feel firm, consistent with comfort and protection. A slack seat belt is ineffective to the degree it is slack. It could also lead to submarining where the occupant slides out under the belt risking serious injury.
One person one seat belt. This applies to carrying children in your arms. Your weight could cause serious or fatal injuries to a child caught between you and a seat belt.
When worn the belt should be free from twists which in the event of a collision could exert a pinching force. The belt should be free from cuts, tears and frays. Care should be taken not to contaminate the belt as you may degrade the material.
If the vehicle has been involved in a serious collision the belt and mechanisms should be checked and if necessary replaced.
When using a seat belt:
- Every time give it a tug to ensure the reels are working.
- Examine by a feel and a glance for cuts, tears and frays.
- Check the tongue is secure in its housing every time.
- Clean according to the manufacturer’s handbook.
Children and Seat Belts.
All children need to be properly restrained. There is a 2 fold reason for this. Firstly the protection of the child in the event of collision. Secondly to prevent the child from distracting the driver.
Adult seat belts are designed to bear upon the bony part of the body. So this will make them inappropriate for children as they will bear upon soft tissue. It is important to use supplementary seating for children.
Consult your Highway Code and Manufactures Handbook for the correct seat and advice on proper fitting. Rear facing child seats should not be used in the front when there is an airbag fitted. The deployment of the airbag to the back of a child’s head can cause serious injury and even death.
If you look on the inside of your passenger door there will be a place where you can turn the passenger seat airbags on and off. Normally use your ignition key for this.
© Liam Greaney