Reflection

My design has changed quite a bit from its first iteration.

My first version of this concept involved the user dragging the sled as it skids along the ground, overcoming the mud and silt. This would be achieved through low friction skids made of Delrin Polymer and the user would drag it behind them. This very notion proved hard to achieve. The combination of mud and debris would make it very difficult to carry a load over this kind of surface, even with the use of this special material. Loads in excess of 60kgs would be incredibly difficult to overcome, as I experienced through my full scale experiments revealed.

Through the addition of wheels, I was able to overcome this problem. I originally wanted to avoid the use of wheels, as traditional wheelbarrows would be immobilised in the deluge. But by positioning the wheels toward the rear of the product, as well as using large, wide, pneumatic tyres, the likely-hood of this happening was drastically reduced.

The initial size of my product was unpractically large. Its width was meant to allow 2 bodies to be laid on it side by side. This was incredibly impractical, as the weight of this load would exceed 100kgs, making it nearly impossible to drag along the ground in my products current form.

My product was then given a diet. It was slimmed down significantly, only allowing room for 1 body, and the profile trimmed down to make an easier frame to transport. My materials were narrowed down, no longer would I use the expensive Delrin, as it was no longer required due to the addition of wheels. The chassis would now be made completely of High Density Polyethylene primarily for its cost and its ability to be moulded.

Rationale

"The Runner" is a product designed to aid in the rescue and recovery effort following a natural disaster, the disaster used as a case study for this design was the 2004 Indonesian Boxing Day Tsunami.

Early on in my design I outlined what I required from my product.

- It needed to be cheap to produce

- It had to be easy to transport

- It had to serve more than one purpose

- It had to be robust

Rotationally moulded out of High Density Polyethylene, the chassis is still, yet light, allowing it to carry loads greater than a human can carry without mechanical assistance, while still being manoeuvrable. Manoeuvrability is a much needed trait, as the user will need to navigate through debris and rubble.

Mounted on either side of the chassis are large wheels with tough pneumatic tyres allowing a manageably plush ride without the need for heavy suspension systems. The tyres are completely removable, allowing the product to be transported in broken down, grouped parts, reducing storage size and logistic costs.

The main purpose of "The Runner" is to help survivors transport their shelter boxes from the refuge centre to the camp site. Shelter boxes are large and heavy scaling 600x600x300 and weighing upwards of 50kgs. Normally this would require 2 volunteers to help move them to the desired spot, but with the use of the runner this cuts people required down to just one, the person doesn't have to be particularly strong either, as the mechanical advantage provided by the wheels allows the sled to roll along the ground.

"The Runner" serves a second purpose, it scales 1400x500x300 and is also designed to be able to support an injured or fatally wounded victim of the Tsunami. The typical male Indonesian is 1600mm tall, so, with strapping support, a victim is able to be transported out of the impact zone to be processed and buried. This is a vital process, as corpses create substantial health risks, and after impact many bodies are left strewn all over ground zero. Traditionally, bodies would be carried by hand, or, less respectfully, carried in a wheelbarrow. "The Runner" provides with a more respectful, yet equally effective method of corpse extraction.

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