A cable-assist harvester ready for action.

By Andrew McEwan
andrew@cmo.co.za

The use of technology in harvesting is a given. Technology is what enables us to harvest trees in a safer way, more productively, with less environmental impact, while achieving higher levels of quality and reducing social impacts.

The very process of ‘modernisation’ which our industry is currently experiencing is really all about looking for new or existing technology that can improve an existing job that is deficient in some or other way. This does not always have to result in the introduction of machines, although this is clearly a global trend.

However the question is, what technologies are appearing that could make a difference to the way that we carry out harvesting? In this article we will first examine technology that is primarily aimed at improving harvesting safety.

The first technology that is clearly gaining ‘traction’ is the use of cable assist machines to enable ground-based machines to operate on slopes that would not otherwise be possible. These machines either have an on-board winch with a cable attached to a secure point upslope, or an anchor machine equipped with a winch located upslope and the cable attached to the logging machine.

This technology is able to keep the operator safer and has the potential to reduce harvesting costs on steep areas. The main purpose is to assist with traction and stability, thereby extending the slope limitation boundaries.

The systems can be used with full ground based systems (e.g. harvesters or forwarders) or cable yarding systems (e.g. felling machines and cable yarders). They are mostly used in countries with large areas of steep slopes, such as New Zealand, Austria, Switzerland and Canada. Even though cable assist technology is becoming more common, it is not predicted to occupy a significant percent of the global machine population as most logging areas do not require this technology – which comes at a cost.

A lot of research and development has gone into improving the safety of the operator in the cab, and cab ergonomics. Researchers and machine manufacturers have realised that there can be significant productivity improvements made by better managing the operator and his/her work environment.

The vision of the operator from the cab improves with each new machine model. Operators must have good views of the work object (the tree – from top to stump with felling machines), the surrounding site and the relevant parts of the machine. Windows are becoming larger and are often curved, the machine is designed with contours to offer better views to the ground, and if necessary the cab can be levelled to maintain the good view.

Technologies such as ‘heads-up’ displays are emerging in forestry machines that allow core information to be projected onto the cabin windows, at automated convenient times when the operator should not be distracted, to ensure that the operator does not have to continuously glance down at the monitor.

Windows are also starting to incorporate self-darkening technologies that respond to the brightness of the sunlight entering the cab. Heated seats in cold climates are now common; as are climate controlled cabs in warmer climates (although sadly the air-conditioner must be one of the components that machine owners in South Africa are slowest to repair).

New air suspension seats are able to reduce impact on the operator’s body, especially with extraction machine such as skidders and forwarders; and are able to keep the operator productive due to improved concentration for longer periods during the shift.

Even though seats that are able to swivel to the rear are common with forwarders and harvesters, they have strangely not yet been fully adopted in skidders. Few skidder manufactures offer them as standard and only some include them as optional. It is understood that there are significant costs involved in redesigning the cab and changing other driveline components to allow the seat to swivel to face the rear.

However, the improvement to operator ergonomics and the resultant obvious improvement in productivity will have all skidder manufacturers including swivelling seats in their machines in future.

For optimal ergonomics and productivity the operator seat should be able to face towards the rear of the skidder.

After all, we can’t claim to care about operator welfare and then expect them to drive for half the day in a distorted position while reversing the skidder.

In conjunction with improved operator seating, developments will continue with operator controls. This includes the seat and control positions to be customised for different operators. The controls themselves are undergoing continuous development to minimise operator hand and finger movements. New ball-shaped controls permit the operator to control the machine with a very natural hand position and negligible finger movement. However, operator preference and cost are still important factors, and we should see various controls being available only as options for some time to come.

Touchscreen monitors are now commonly used for ease of operator interaction. The monitors can and will increasingly have multi-function uses such as trouble shooting diagnosis, internet based communication with management is possible (e.g. WhatsApp, Skype), taking photos and video clips for problem diagnosis, pre and post inspection checklists with automatic fault reporting, refuelling data input, transmission of production and product data with GIS positioning, real-time compartment map updating, worksite risk alerts based on machine location in compartment, and presentation of any other data related to other sensors and monitoring systems on the machine.

In the next issue of SA Forestry we will examine more safety and ergonomic technologies being applied on logging machines.

Operator vision from the cab is being constantly improved.

*First published in SA Forestry magazine, Feb 2017