Eltirus

Management of mobile equipment idle time is a simple but effective way to reduce CO2 emissions and costs on site. Eltirus founder Steve Franklin explains.

Did you know that for every litre of diesel burned, 2.68kg of CO2 is produced?

As you might imagine, this can really add up over the course of a year, let alone the life of the machine. But other than replace your diesel equipment with machines powered by alternative fuel sources, what can you do to reduce the amount of diesel consumed on your site, reduce CO2 emissions?

Reduce idle time
Idle time is any period where the engine is running, but the machine is not working. Common causes of idle time:

• Loading tool operators under trucked who are waiting on trucks
• Machines left running on the go line at start (or end) of shift
• Machines running through breaks

In a 2014 article called “How much is idle time costing you?” Caterpillar estimated that it was not unusual for 40-50 per cent of total running time to consist of idle time. This is a jaw-dropping number.

In the ten years since that article, this percentage will likely have dropped in line with the broader roll-out of auto-shutdown systems, but I suspect that it is still a large number and one that you probably want to do something about.

Excessive idle time not only unnecessarily burns diesel and produces CO2 emissions, it also reduces component life, results in unnecessary servicing and oil changes, burns through warranty hours and reduces resale value. Would you pay the same for the second-hand machine with 10,000 hours on the clock or the one with 14,000 hours through excessive idling?

So, what to do about reducing idle time? First, you must have a system to monitor it. Most modern machines will have some form of telematics system that will help you do this – Caterpillar Vision Link, Komatsu Smart Quarry, Volvo CareTrack, are all good examples.

Secondly, you need to decide what target you are going to set and determine the value of the likely improvement. Thirdly, you need to put in place a program to drive down idle time – some of the ways that this can be done include:

• increase operator awareness of the issue.
• reduce idle time at shutdown. Most modern machines can be shutoff instantly and don’t need to idle for long periods to ‘wind down’.
• shutdown trucks waiting more than five minutes at the loading or tipping point.
• minimise warm-up on the go-line – five minutes should be plenty.
• use auto-shutdown systems wherever possible.
• fit electrically powered air-conditioning/heating systems in machines so that the cab temperature can be maintained during breaks without the engine running.

Key to the effectiveness of any problem like this is continual feedback to the crew on how they are doing against the targets and the importance of them.

Excessive idle time unnecessarily burns diesel and produces CO2 emissions. Image: Eltirus

Match the equipment to the job

When we think about engine life, we tend to think in terms of hours run. However, the real measure is litres of fuel consumed by the engine during its life.

You could in a way liken it to a bank account that starts with say $100,000 as an initial balance and for every litre of fuel consumed, the balance is debited until it hit zero and the engine needs rebuilding.

Consume a large number of litres per hour and the engine life is shortened – consume it more slowly and the engine life is lengthened.

Manufacturers characterise this in terms of duty cycle and produce tables showing estimated fuel consumption in line with low, medium and heavy duty. These tables are very instructive, because not only do they help us predict fuel consumption, they also help us understand how hard the machines are being worked and how well matched they are to the job.

I recently saw a post from a company switching out an older loader for a new one and noting with some pride that it had achieved close to 30,000 hours on the initial engine. While this was clearly a credit to the team looking after it and the manufacturer, in reality it also indicates that the duty cycle was low, because if it had been in the medium duty to high range, the engine life would have been more like 16,000–22,000 hours.

Another issue we see is that the machines being purchased are often too big for the role they are being deployed in. This is often the case with face loaders – due to a larger truck size being used, a larger wheel loader is needed to load that truck and so the loader often ends up underutilised.

And finally, you need to consider machine size growth over time. Replacing the machine that you already have with the latest version of it may seem logical but may not be the best choice. If we take the Caterpillar 980 as an example, it has grown from an initial 175kW to the current machine rated at 307 kW – this is a big jump, particularly when you also factor in just how much more productive the machine is generally through better technology.

Some years ago, I worked with a site to help them replace their face loading tools. We determined that they could get the work done with a size class smaller (than they were used to) and ten years on are doing just fine with the smaller machines and have saved themselves a fortune in the process.

Excess equipment

In the absence of accurate idle time data, knowledge of duty cycle can help you gain an accurate picture of what is occurring in the operation.

Many years ago, I was asked to review the number of sales loaders on a large operation. The quarry had six large sales loaders and was hearing continual complaints from the operators that this was not enough. Luckily, they had good fuel consumption records and hour meter readings for each machine.

On analysis, the most remarkable thing came to light. The fuel consumption on most of those loaders was so low that the only answer was that they were spending most of the time idling.

Only a couple were where you would expect, and further investigation found that the truth of the matter was that the ‘old hands’ would settle themselves out of sight near the slow-moving stockpiles while two young operators did most of the work on the fast-moving stocks. Needless to say, they didn’t get any more loaders.

Shutdown trucks waiting more than five minutes at the loading or tipping point. Image: Eltirus

Work it hard or shut it down
When I operated machines, the cardinal sin (and a sackable offence) was to be caught by the boss doing nothing.

I learned early on that I was far better off to create “busy work” and keep the machine moving, no matter what, as to be caught stopped was going to get me into a lot of trouble. And so, roads that didn’t need to be graded were, roads watered that didn’t really need to be watered were wet, material was moved unnecessarily from place to place and so it went on, all to ensure that we were not caught “doing nothing”. It took me a while to realise this was a foolish viewpoint.

It is much cheaper to park a machine up if there is no productive work for it and sit the operator in the crib room (or send them home) than operate a machine for the sake of it.

Some of you will no doubt think this is nonsense, after all, the “cost” is just the diesel consumed, you have to pay the operator and the lease anyway, but in reality, this is not the complete picture, you also have to “pay” the operating cost of the machine too – this is just not a cost that you immediately see. Operating any major machine is expensive and forcing an operator into busy work is poor for morale.

Replace older equipment
I mentioned earlier that manufacturers create duty cycle tables for you to get a sense of fuel consumption. One way to use them is to help justify machine replacement. By way of example, I came across a site with many Cat 773B haultrucks. Given their age, I commented on them to the manager. His response was that they were the lowest cost machines they had and there was no plan to replace them. Out of curiosity I sat down and did a quick fuel burn comparison between the existing trucks and current models. The newer machines had a 41 per cent higher rated payload and a 32 per cent lower fuel consumption. These are big numbers.

At a time when companies are all the more cost and emissions focussed, replacement of older generation equipment just might be good for the bottom line and the environment too (not to mention your operators’ health).