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 Technical

Safety Devices produce a vast range of roll cages which are developed and manufactured to the highest industry standards.

Products under development are installed directly into vehicles by our highly accomplished and experienced development engineers who ensure not only a product that fits neatly into the space available, but also provides the best ergonomic solution. The prototype is then laser scanned to impressive accuracies of +/- 0.1mm using our FARO Arm, a portable Co-ordinate Measuring Machine (CMM), to reduce measuring time and human error. This data is then used to produce the initial centre line model followed by the full assembly. The development is then transferred to our skilled CAD engineers who use the latest SolidWorks CAD software to optimise parameters such as materials, diameters and tube gauges to reduce weight but maintain strength. Multiple solutions are tested with Finite Element Analysis, which provides accurate stress analysis for the roll cage and highlights the most appropriate solution. Our final designs are submitted to the Motor Industry Research Association (MIRA) for independent verification.

All design information is exported from SolidWorks directly to our modern manufacturing facility via our unique, purpose built software system. This enables programmes to be loaded directly onto our full Computer Numerically Controlled (CNC) bender, plasma tube and plate cutters, thus eliminating human error. It may take a skilled engineer many minutes to cut a steel tube end to create a join with another - it takes our CNC machinery only seconds to produce a more accurate and smooth result.

All products are assembled and fabricated using fixed manufacturing jigs to ensure minimum weld distortion, which in turn results in an unrivalled installation. ‘No go jigs’ which have zero error tolerance, are used as a final, fail safe check.

To comply with rigorous quality control procedures implemented to satisfy our ISO 9001 quality management standard certification, the FARO Arm is regularly used to scan the finished components as they leave the warehouse, the results of which are directly overlayed and compared to the prototype to ensure accuracy has been maintained throughout the processes.

We believe this extensively detailed and specialised engineering process is what makes Safety Devices roll cages some of the very best in the world.

Choosing the right roll cage

Making the right choice of roll cage is very important, especially when considering the extreme circumstances roll cages are designed for. It is essential to check all class rules and regulations as well as MSA/FIA requirements for your events.

Road Use roll cages

Road use roll cages are made to the same exacting standards as competition roll cages, using the same high grade materials, however, they are often not as complex. They will usually still offer substantially more protection compared to a standard vehicle without a roll cage.

Road use applications are usually satisfied with just the rear (or ‘half’) roll cage, although many people fit a full roll cage as this is considered to enhance the overall look of the vehicle. This can be further improved by fitting extras like door bars and competition harnesses. Road use cages are easy to fit by a competent person as they simply bolt in place. A full fitting kit and instructions are supplied with every cage.

Motorsport (competition) roll cages

Motorsport roll cages must conform to the rules outlined by the sports governing bodies. We are happy to advise whether specific products comply to your requirements, however, for your reference, we have also included links below to the common requirements of the MSA and FIA .

International Motorsport Events

Pre January 1, 2003
FIA regulations stated that as long as a ROPS was designed to specification laid down in FIA Article 253 Section 8.2, then no certification or homologation was required. However , if an reputable roll cage manufacturer were to build a cage to its own design, the design must be proven to withstand loads of 7.5w daN vertically, 5.5w daN longitudinally and 1.5w daN laterally at the main hoop and where w = vehicle weight + 75kg. The test could be completed by the manufacturer and a certificate would be issued by the MSA.

Post January 1, 2003
In January 2003 the regulations regarding homologation of roll cages for international events changed significantly. The main changes were that the front roll cage must withstand a load of 3.5w daN (w = vehicle weight + 150kg) applied to the top of the windscreen at an angle of 25 deg x 5 deg (+/- 1 deg) ( reference drawing No. 253 - 38B).

The complete roll cage must also be designed to withstand a vertical load of 7.5w daN (w = weight of the car + 150 kg) applied on the top of the main roll hoop ( reference drawing No. 253 - 38B) .

The door aperture must have a vertical member if the distance between initial downwards bend and the final mounting exceeds 200mm ( reference drawing No. 253 - 4) .

The 'B' post hoop now requires two diagonal members as well as being gusseted in the centre ( reference drawing No. 253 - 4) .

The roof above the driver/ co-driver must have two cross members installed. For competitions without co-drivers, only one diagonal member to be fitted with its front connection to be on the driver's side ( reference drawing No. 253 - 9) .

The actual certification to be carried out by an institutionalised test house independent to the manufacturer.
 

Important Information on Homologation

No certification can be cancelled - cages certified before 1st January 2003 continue to be homologated.
If the car involved is not homologated itself by the FIA , it cannot be used for international events and therefore a certificate cannot be issued for a roll cage for that car.

There are , however , deviations from this in that some National events take place overseas as part of an International event but are run to the MSA National A regulations, which do not require roll cage certification.

Bolt-in or Weld-in?

For the majority of the cars used in motorsport, we offer the following roll cage options :

  • 6 point bolt-in roll cages (bolt to the floor in 6 places)
  • Multi-point bolt-in roll cages. These are essentially an upgraded 6 point with additional attachment points to the body.
  • Weld-in roll cages. These roll cages are sold as kits with all tubes bent and profiled as required and they include all mounting brackets and plates.

Materials

In order to guarantee that our roll cages will do what they are designed to do should you be unfortunate enough to have a serious crash, we only use the highest quality, reputably sourced job-specific materials - your life and our reputation depend on it.

CDS Carbon Steel

Otherwise known as Cold Drawn Seamless Carbon Steel, this material is used to manufacture all of our standard motorsport and 4x4 roll cages due to its conformity to FIA material specifications and because it offers two essential characteristics: good elongation and receptiveness to welding. Compared to T45, CDS it is a very cost effective material.

T45

Initially used only for aerospace applications, T45 has been used in the manufacturing of Safety Devices’ roll cages for quite some time. The advantage of T45 is that it has a tensile strength approximately twice that of the standard Cold Drawn Seamless tube (CDS). Due to T45’s high tensile strength, we can manufacture the roll cage using tubing of the same diameter but of a thinner gauge (wall thickness). As a guide, this equates to a weight saving of approximately 0.5 kg per metre of tubing or 10 - 15% of the total roll cage weight when compared to CDS. However, this does come at a cost: a roll cage manufactured in T45 is significantly more expensive than its CDS equivalent and is therefore only really required by competitors at the higher end of the motorsport spectrum.

ERW mild steel

Electrically Resistance Welded (ERW) mild steel does not have an adequate tensile strength to comply with article 253 section 8.3 of the FIA regulations relating to material specifications, and is only used for non-structural applications such as roof racks where a durable product is required.

Cr (Chrome Molybdenum) steel

Although popular with some roll cage manufacturers, we do not use Cr in any of our tubular products because its quality consistency is problematic and energy absorption far less effective than T45.

Paint finishes

Finished bolt-in roll cages are normally supplied with a hard-wearing black powder coating, although other colours are available (red, silver, white, grey and blue). Bolt-in roll cages can also be supplied unpainted by special request. Weld-in roll cages are always supplied unpainted. Any external roll cages or parts are treated with a zinc enriched coat, followed by the final black coat. This combination provides a similar durability to the vehicles original paint work.

Technical Impact Padding

Current regulations

Article K section 1.3.6 (Competitor Safety) of the MSA blue book states that "Where the driver's or co-driver's bodies or crash helmets could come into contact with the safety cage, non-flammable padding should be provided for protection", and section 1.6.6 states that "It is recommended that roll bar/roll cage tubes within 150mm of a vehicle occupant's helmet are covered with a suitable energy absorbing material. A number of suitable materials are homologated by the FIA who publish specific regulations for the fitment of such materials".

The FIA regulations regarding roll cage padding can be found under article 253 section 8.3.5 and state "Where the occupants' bodies could come into contact with the safety cage, non-flammable padding must be provided for protection” and “Where the occupants' crash helmets could come into contact with the safety cage, the padding must comply with FIA standard 8857-2001, type A (...) and must be permanently fixed to the cage.”

Constructed from EAFSD3 semi-rigid energy absorbing foam, our homologated padding is designed to be mounted primarily on the roll cage in the immediate head contact area, with the domed face pointing in the direction of impact. However , use on all areas of the roll cage structure which the occupants ’ bodies are likely to contact in the event of a roll over/accident is advisable.

To achieve the FIA standard 8857-2001 for both impact and fire resistance, Safety Devices padding was tested by the UK's TRL (Transport Research Laboratory) and had to meet the following Type A criteria before approval was granted:


1) A head form weighing 6.8kg and fitted with an acceloromet had to pass a dynamic impact test of 7.0 metres/second with a peak acceleration of 300g in both hot (38deg C) and cold (7deg C) conditions.

2) After exposure to a 790deg C propane flame for 30 seconds the padding had to self extinguish within 10 seconds.

Result

Safety Devices padding easily achieved the above criteria with an average deceleration figure of 245g and an average self-extinguishing time of 4.5 seconds, resulting in our padding being issued with homologation number CP.002.02.A.

Confor Foam offers a unique combination of properties ideal for protective padding applications. The illustrations below (click to enlarge) demonstrate the significant damping characteristics that make the product so popular.