University Chapter of SAE and included comments such as; ‘effectively managed design engineers’, ‘weekly reporting’, ‘full life-cycle experience, power train and testing experience’. The various race positions of the previous events were also given in testimony to the competitive nature of the Baja event. This competition gave the individual a strong CV and a network of contacts to receive it.

Water Wading Event
This is a spectacle whereby the car uses its built-in flotation and pneumatic tyres to traverse very deep waters whilst floating on the surface. This is not a small achievement given that Baja Vehicles weigh between 485 and 650 pounds. In the case of the Baja Event we visited the water reached a maximum depth of 42 feet and came with a full compliment of four small ‘gators (not for the faint-hearted). Water testing also creates different challenges with the engine CVT belts as it tends to cause slipping when they come into contact with water. It is also difficult for the Baja Vehicle to exit from the water as this involves climbing a wet, muddy bank. There were three stages to the water event;

1. The initial decline into the water tests flotation. The entry to the water was via a steep decline which submerses the vehicle body briefly. After a controlled descent the vehicle was tested in the shallows for buoyancy and stability in the water. SAE-UK.org video footage is available online at at www.VehicleTechnology.org/baja.

2. Stability is tested by a 30 degree tilt test across the width of the vehicle to establish whether it would turn over easily. Vehicles that pass then throttle-up and drive through the shallows before coming back up to the ramp for the full water event.

3. The water event starts with a rapid acceleration down a moderate incline, crashing in to the water where the buoyancy aids keep the vehicle afloat. Vehicles with chevron patterned tyres were particularly effective as the chevrons had the same effect as steam paddles. Once in the water and afloat, the object is to navigate around 3 buoys evenly spaced to achieve a slalom-like course. The return across the water’s surface culminates in the difficult return on to land. The Baja vehicle is back-wheel-drive meaning that it effectively swims on to land which is quite difficult. We have montaged the images above to try to recreate the panorama and experience of watching an amphibious 4x4, weighing 600lb, going into the water. SAE-UK.org video footage is available online at at www.VehicleTechnology.org/baja.

The driver pictured was a young female student as this event suits a lighter driver. The flotation devices may be successful in the water but their

ground clearance present a real hindrance in the mud pit event, which is covered next.

Mud Pit
The mud pit created was 5m wide and 30m long with single entry and exit points, vehicles had a tow rope attached prior to starting (in case they got stuck). The mud was obtained from an adjacent pond and was topped up by a water truck as well as from the adjacent pond. An unsuccessful attempt to cross the Mud Pit is montaged below.

The mud pit required continuous maintenance, the Florida sun causes rapid evaporation which leaves hard deposits that cannot be overcome easily. The application of water, a shovel and maximum effort were required throughout. We followed the progress of the Auburn University Vehicle in the Baja Mud Pit. The pictures below show the towing of their vehicle back out of the Mud Pit though they do not convey the sense of disappointment of the team. They made it one-quarter of the full distance across. The proximity of the flotation devices reduced the ground clearance and prevents a successful mud pit event.

The Sled.
The sled test assesses the pulling power of the vehicle. This is done by driving along a short track attached to a device called the sled. During the forward motion of the vehicle the weight of the sled increases in the following way. A metal water tank measuring 1m x 1m x 0.5m deep ascends an incline on the sled of approximately 15 degrees during the course. A steel friction shoe underneath the sled of approximately 0.5m2 area with rubber friction pads created a frictional resistance to the ground. During the sled’s motion, the weight moves up the incline, driven by the rotational action of the rear axle linked to a chain link system which then powers a wire pulley system – drawing the weight higher and increasing the force between the sled and the ground. It may be simpler to view the SAE-UK.org video footage is available online at at www.VehicleTechnology.org/baja.

It should be noted that a log version might be a cheaper alternative, where logs are chained together so that the initial load allows the Baja vehicle to pull away. Then as the vehicle travels more logs are pulled behind until the vehicle comes to a halt. Sled Testing is conducted on asphalt where possible, avoiding loose surface material. It should be noted that the log alternative may damage an asphalt surface.

Team Members are highly dedicated to their group project, with individuals fired up for what is a very positive learning experience. The atmosphere at the event was infectious and highly enjoyable for all present including sponsors.