Most tunnels in use throughout the world are either hand made by tarpaulin manufacturers or made on a machine whose prime function is to manufacture air ducting. In both cases the choice of fabric is a lightly woven base material which has been surface coated with a thermo-plastic resin (pvc or similar). The choice of fabric is critical to the manufacturing process as both the hand-made and machine made tunnels rely on the material being able to be heat welded.
In the case of the hand-made variety, pockets are formed on the outside into which a reinforcing pipe is inserted as the method of holding the tunnel in the required shape. These pipes are generally a plastic material approximately 15mm in diameter spaced at 150 – 200mm intervals and cause the floor of the tunnel to have bumps which can create a bruising hazard. In the case of the machine made (air ducting type) the shape is retained by way of imbedded continuous spring steel wire usually around 3mm in diameter and most often spaced at 100mm intervals. This dimension is referred to as pitch. In poor quality tunnels of this kind, the wires are sometimes neither galvanised (which can cause rusting) nor tempered steel (which can cause the tunnels to go out of shape) plus some have a wide pitch. Both kinds of tunnel need the thick coating of plastic to form the welds that hold the tunnel together and is possibly the worst fabric that could have been chosen as a base fabric for tunnel manufacture. The plastic coating has a slippery surface and when wet can cause a dog to completely lose their footing. There are at least two manufacturers (one in Poland and another in Canada) who surface treat their plastic to offer a surface that is vastly superior to the plain plastic. However if our tunnels could be made from a fabric that is not plastic coated then the result would be considerably safer.
In 2012 I commissioned an Australian company to manufacture a tunnel from woven webbing. From a technical stand point the prototype was a success but financially it would have meant a finished product far too expensive for our market plus it was difficult to hold the diameter dimension even.
For a number of years our company imported and sold an air ducting type of tunnel but we became increasingly disgruntled with the quality. In a recent experiment we heated a portion of the fabric to melt away the plastic to expose the warp and weft fibres. We were astounded to find that the base fabric represented little more than that which you would find in a gauze bandage. It is no wonder that the combination of dog’s claws, the ever increasing speed of the dogs and our harsh levels of UV in New Zealand was leading to the premature demise of these tunnels.
During my career in a different industry, I was struck by the comparison of the New Zealand and Australian economies. In many instances trade custom was dictated in our case by our British heritage but in Australia was more influenced by American trends. This has extended to agility in many aspects, not the least of which is our method of graduation. In New Zealand graduation is earned by “winning out” but in Australia by the accumulation of “clear rounds”. In my opinion this has led to a more aggressive style of agility in New Zealand which in turn puts more strain on the equipment. This observation is not intended to classify the two agility populations as the best canine athletes of Australia and New Zealand are very much on a par but here we have a greater population of dogs with an aggressive agility style.
During my judging opportunities in Australia I quickly learned that it is necessary to adjust the tunnel mouths after every 6 – 10 dog passes ssince the tunnel bags in use in Australia allow the tunnels to move about which creates different experiences between competitors. I often wondered why tunnel bags were so popular in Australia until I became more aware of the custom in America. In that country a great many of the events are held indoors and pegging of any kind of tunnel “holder” is not practical.
It was probably these experiences that gave birth to my opinion that pegging of tunnels is superior to any kind of sand bag and led to the development of a soft collar that can be pegged. Looking back I was probably influenced by the traditional methods of tunnel fixing in New Zealand even though I, like many others were nervous about any fixing method that used solid materials (notably timber and/or steel).
It is interesting to note that whilst New Zealand seems to be going through a phase of developing a thirst for tunnel bags, the Australians are tinkering with soft collars.