Trail Development

Construction Techniques


The actual construction techniques that are used in the development of a trail are vitally important to the success of the trail. It is no use laying out a beautiful trail if you are going to have serious and unsightly erosion created as a result of poor construction methods. Take short cuts at this stage and your maintenance bill is going to be much higher later on.

Tools that you will need

Among the useful tools that you should acquired is an Adze. This can be used for leveling paths and excavation. Other implements that probably will be needed include saws and shovels. If timber is going to be used then it should be treated to conform to ISO standards for outdoor use.

Path width and clearance height

The width of the path can vary according to the type of terrain and what is practical. However one should aim if possible, for a tread of about a metre wide. You will find that this will allow for the encroachment of vegetation between maintenance. The clearance height should ideally be about 2 metres, especially on backpacking trails where it is more difficult to keep bending down to negotiate low branches. To keep the trail as natural as possible an occasional lower branch can be accommodated. Thick, fast growing bush should be cut well back and any trees that are in danger of falling across the path should be removed.

Mountain Slopes

The ascent of mountain slopes needs special techniques. Rather than a direct, steeper ascent, it is usually better to zigzag the path up the incline. Care must be taken, however, not to overdo this as you will find hikers tend to cut corners.

Periodically on an ascent a reverse incline needs to take place in order to lead rain water away from the trail. This is also important when the trail crosses the course of mountain streams. In addition, treated wooden logs should be securely anchored across the path to act as erosion barriers. Trees, rocks and thickets are ideal places to go around thereby varying the degree of angle of the uphill.

The wooden steps need to be securely anchored and it should be considered that it is far easier for a human to take a larger step 'up' than 'down'. Although hikers use these as steps, the most important thing to remember is that they are primarily there to prevent erosion.

Logs can also used as a retaining mechanism to prevent subsidence especially on very steep banks. On the bends of zigzags logs should be placed across the path to lead rainwater away.

Curb logs can be used in places were there is a danger in subsidence of the path

Metal or wooden droppers must be driven into the ground firmly to make sure that the steps are able to withstand the wear of hiking boots. To prevent possible injury the tops of these stakes should not protrude above the top of the log.

In the above illustration we see the right way and the wrong way to secure water bars .

 

Water bars are basically the reverse of steps where is steps the earth is packed on the higher side to provide a platform, with water bars the earth is packed on the lower side (see above illustration)

On a mountain side the cut and fill method of construction should be used. Here the bank should be cut away on the higher side and the material deposited on the lower side of the tread. There should be an outslope on the tread of the trail of 3-4 degrees. The cut bank must be stabilized as far as possible to prevent erosion. Loose rock should be removed from the tread but firm rock can be useful in stabilizing the path.

 On very steep inclines, tyre ladders can be useful. However, extra care must be taken to make sure that they are securely anchored and that none of the steel belt is a danger to those who use the ladder. Solid steel ladders and chain ladders are also used successfully.

If timber is used for ladder construction, only properly treated timber must be used. The cross members should be bolted rather than nailed or wired. Wire could be used as a fail safe device. All constructions should be checked for potential failure at least once a month.

Crossing Vlei (marshland)

Many of our wetland area are very sensitive to disturbance. Where a trail has to cross such a place special care needs to be taken. A wooden walkway is one way of overcoming this problem but tends to be rather expensive to construct. Where the vlei is not to deep, large rocks placed as stepping stones can do the trick. Alternatively, log bridges can overcome the problem.

Crossing Slippery Areas

It is sometime necessary  to anchor a chain as a handhold in slippery areas.

A chain on Rooi ivoor Trail

Crossing streams

To Bridge or not to Bridge, that is the question? Bridges tend to need a lot of maintenance and can become very slippery when wet leading to the possibility of injury and resulting in possible claims. I believe that wherever possible bridges should be done away with and an alternative use of steel cable and strategically placed rocks utilized.

 Crossing fences

Inevitably most trails have to cross some form of fence. Relying on hikers to open and shut gates is going to lead to trouble. It is far easier to provide some other means of crossing these obstacles. It is definitely not satisfactory to leave hikers to find their own way over barbed wire fences especially when there are cost effective alternatives.

Steps, up and over the fence can be the answer. A pole for the hiker to hold onto can give those with heavy rucksacks an additional support.

Ladders can be the answer especially for high game fences. Just make sure that they are firmly anchored.

A dogleg style can also work well.

I have also seen what I call a 'Creep through' work very well. Here a wooden frame is inserted into the fence and the middle strands removed.

Our thanks to Jaynee Levy and others for the use of some of their illustrations on this page