Geometric Limitations of Vehicle

Contents

• Angle of Approach
• Angle of Departure
• Angle of Approach on Descent
• Angle of Departure on Ascent
• Ramp Angle
• Side Angle of Maximum Articulation
• Cross Axle Situation at Maximum Articulation
• Restricted Vision Problems
  • Wind Screen Pillar and Internal Roll Cages

Introduction

Before you start adventuring into any off-road situation you need to understand your vehicle’s “Geometric Limitations” – In reality this is just a fancy name for how and what the body shape, under body transmission and suspension parts will allow the vehicle to travel over on varied terrain while taking into account the laws of physics, dynamics and stability.

Without this knowledge there is likely to be the embarrassment of damage to the vehicle or the terrain as well as to the driver and any occupants. To keep things simple, these fundamentals are captioned photographs.

This content was developed by and owned by Paul Sinkinson, Xplorability owner. Paul is a 4wd Defensive Driver Training Consultant/Trainer and Programme Developer.

By being aware of the following Angles and Limitations it will help you to understand more fully the capabilities of the 4wd vehicle you use.

Normally, this theory programme runs alongside full practical training and perhaps sometime in the future we can look at accompanying videos for that but in the meantime, absorb the information and step outside and check out how it applies to your vehicle.

Angle of Approach

Determines what the vehicle is able to climb up

Angle of Departure

Determines what the vehicle can descend

Angle of Approach on Descent

Determines if vehicle can exit a descent

Angle of Departure on Ascent

Determines if a vehicle is able to exit an ascent without connecting with the terrain at the rear

Ramp Angle

Determines if a vehicle can cross the centre point of a climb

Ramp angle is also the angle at the centre lowest point between the axles

Side Angle of Maximum Articulation

The maximum SAFE side slope angle

Beyond this the vehicle can rollover

Side angles are DANGEROUS – vehicle CAN ROLLOVER

Rear Wheel lifting off terrain – Next stage is a rollover

Beyond this point can be a rollover

Vehicle at rollover point

Front wheel is now off the ground – Rear wheel about to lift

Cross side angle at maximum articulation – DANGER!

Side angle at maximum articulation

Cross Axle Situation at Maximum Articulation

Front wheel off the terrain and opposing rear wheel also off the terrain

Front and opposing rear wheels off the terrain

Restricted Vision Problems

Wind Screen Pillar and Internal Roll Cages

It is Important to explain to 4wd drivers that, as you may see from time to time in crash photographs of vehicles with Internal Protection Cages installed or Snorkels that they encroach into the drivers area of vision to the extent that vehicles approaching from the left (left hand drive and similarly the right in right hand drive) at junctions or approaching from the left on left hand bends can not be seen clearly and that a number of accidents appear to be either T boned damage to vehicles or vehicles being T Boned by vehicles. On the approach to junctions and left hand bends (right on RHD) the drivers must therefore be cautious and make an effort to ensure that they are aware of any traffic or obstacles that could be blocked by the windscreen pillar and the internal cage support leg or the Snorkel itself.

Next Article: Hazard ID, Safety and Environment

Check out other work by Paul, fiction thriller novels here.

Copyright

This content was prepared for the Off-Road Discovery Website by Xplorability 4wd Training

The Content - All Photographs and Photographic Copyright and All other Rights other Reserved October 2017. S.W. France This content may not be copied or reproduced without the written consent of Paul Sinkinson – Xplorability Training.

For Use Only in 4wd and Light Vehicle Driver Training.

Not for Re-Publication, Distribution or use outside the Xplorability Training Programme