Types of glass found on vehicle's today
Laminated Glass — this is found primarily in windshields of vehicles but is now being used for side glazing and the rear windows on newer vehicles on the roads today.
· Tempered Glass — this type of glass is found more commonly on the side and rear windows and is easily
Broken with a center punch, it will break into small pieces, creating a contamination risk to the casualty's injury's,rescuers and slip hazards on hard road surfaces.
· EPG (Enhanced Protective Glass) — this is a newer type of safety glass introduced as a
Stronger, lighter and thinner type of glass. It utilizes the same principle as laminated glass, with
two pieces of glass sandwiched around a new type of material called PVB (polyvinyl butyral).
This material is considered safer than laminated glass but we will need to use a reciprocating saw
or similar type of glass tool to gain entry at every window location.
· Polycarbonate Glass — some manufacturers are considering using polycarbonate materials for their windows. It should be used initially in non-moving windows, such as the side windows on minivans.
Below is a list of Vehicles with side laminated windows fitted either standard or optional: Enhanced protective glass provides added protection against injury to vehicle occupants in case of an accident
|
Standard |
Optional |
How to deal with these different types of glazing at incidents:
Before any glass is managed use the correct PPE including a dust mask, and preferable cover the casualty in a clear plastic sheet for their protection. Also use a dust mask for the casualty if the situation requires it.
Tempered Glass:
This is dealt with in the normal way with the use of many tools such as a centre punch, pliers, Glass-master, small hammer and so on.
Use full casualty protection, I prefer the use of a small sheet instead of a Tear Drop as it can then be used to push the glass out of the window away from the vehicle, but having said that a Tear Drop can be useful to reach areas that are just out of arms reach with a sheet. Use a small sheet on the floor to collect the glass for removal so as not to contaminate the work area and it also prevents creating a slip hazard, however don't waste valuable resources to clear the glass as more critical jobs may have to take priority. An example of a centre punch can be seen below
Laminated and EPG Glass
Dealing with this type of glass is no mystery. You can manage this type of glass the same way we manage windshield glass. However casualty protection is paramount due to the glass dust that can be produced from cutting it.
If at first we have tried to break the side glazing with a centre punch and after 2 -3 attempts nothing happens, we should take this as a sign that we are now dealing with Laminated or EPG glass.
Firstly we must ask ourselves, do we have casualty access? So therefore is there a need to cut this glass away, this type of glass will not suddenly break like toughened glass did if left unmanaged. So there is no real need to waste time cutting it away, but a good idea may be to cover the glass to prevent any glass particles from flying around whilst carrying out certain cutting evolutions.
A tip for cutting this type of glass with a reciprocating saw is to use a blade of around 6-8 TPI (teeth per inch) this creates slightly larger glass particles and very slightly reduces fine glass dust, a blade with higher TPI at high speed will cause the saw to melt the middle plastic layer of the glass which will in turn coat the blade in molten rubber and blunt it.
An easy way to deal with side door glass is to either cut across the top of the glass with a saw, and then hook the glass out so that you can then lever it down, which in effect folds the glass down the outside of the door and out of the way.
Secondly another way is to cut straight across the bottom of the glass and into the window frame; you can then hook the glass out and pull the whole upper piece down and away completely from the door.
Polycarbonate glass
This will either be fixed with adhesive or by screw type fixings or by other means especially on race spec vehicles, it can be managed by cutting or prying out with spreaders as part of the vehicle or left in situ, it will be of similar plastic to that use for the Tear Drops. If you use a reciprocating saw the blade heat will just melt the plastic and make the saw in-effective.
How do we know what type of glass it is
On some vehicles the glass will be marked either Toughened or Laminated, this will be the easiest way to denote the type of side glazing, there are also other markings which tell us the type of glass and these can be Roman numerals above the country mark, in the below picture the country mark is ( E6 in a circle ) Number 1 is the Roman numeral.
Let us not get to worried, and wast valuable time at a crash scene by trying to read these markings to try and find exactly what type of glass we are dealing with.
Reading the vehicle damage and deformity we should be able to see how the glass has reacted to the impact damage, this will give you a good indication as to what glass we are dealing with.
Keep it simple, if you try to break the side window with a center punch and after 2-3 attempts there is no break, we now know it will be Laminated or EPG glass, so do we need to remove it or leave in situ? Only the situation will dictate this.
If you have the knowledge and are able to decifer the glass markings to determine the glass type, in and ideal situation this will be best practice, but again we must not waste valuable time and delay rescue operations.
Only manage the glass that needs to be managed, but plan ahead, do we want to have to manage glass later into the incident because our plan has changed ? Plan ahead !!
Whilst carrying out some training we found that the use of duct tape to minimise the glass dust created from cutting Laminated glass had little to no affect, it didnt hinder the cutting but the glass dust produced was substantial.
The use of water or shaving foam would be the ideal solution, obviously not forgetting full casualty protection and rescuer PPE.