Production loading is making every move count and thereby making good production.
In moving the earth; it is rarely bid to move it more than once or slowly. In loading trucks with a wheel loader the loader operator is in charge of getting the trucks in position to make minimal moves and travel with the material to be loaded. Get the trucks positioned to where you can load the bucket, back up a minimum amount as possible while turning towards the truck and beginning to hoist the bucket. Keep the loader in an appropriate gear to keep the engine R.P.M s up to make maximum hydraulic response…normally you will load in first gear and then shift to 2nd gear after the bucket is full.
When I load a truck, I will be raising the hoist as I am moving towards the truck, just clearing the sideboard with the cutting edge of the bucket. As soon as the front part of the cutting edge clears the edge of the bed, I start rolling the bucket forward to dump… this keeps the bucket height down, (for safety as well as not dropping the load),truckers hate being ‘slam dunked’.
It does take practice to get the load centered and not spill any over the opposite sideboard on the last bucket… and not hit any sideboards with the loader. A loader will be able to load much more efficiently if the pile that the dozer is stockpiling is not compacted.
Even the largest loaders have to spend valuable seconds ‘breaking out’ hard packed material that the dozer has run over. Have the dozer push it as high as it can and just make the pile longer. The loader can then chase the pile with the trucks. The dozer has to establish the ‘floor’ grade for the loader to maintain as well as determining how far out to push the pile to allow the dozer not to become ‘muck bound’ with material… it takes experience to do this, if you want to move 4,000 – 6,000 cubic yards per shift with one dozer and loader or track hoe.
A loader operator should come into the pile with the bucket on the floor grade, while slightly raising the hoist… do not curl the bucket back unless you are positive you will have a full bucket. If you don’t get a full bucket, just go with what you have or back up and start again… pitching the bucket back down to get another bite will only lift your front wheels and further compact the material under the bucket.
Loading trucks with a track hoe may be the most efficient method as long as the material is higher than a few feet, if the hoe has to chase material it is not efficient. Getting the trucks to get as close as possible is critical with a track hoe, especially when the cut is high… overextending your boom with a full bucket will cause one track to come off the ground or the whole rear of the machine. I have seen trucks destroyed when a track hoe overextends their boom and tips over.
The track hoe operator is responsible for keeping the floor to grade and smooth enough for the trucks to come in close. Sometimes the dozer, loader or blade will come along and smooth it up, however, don’t count on it!
Loading scrapers with a dozer involves timing and teamwork. Getting ‘tagged up’ smoothly and quickly takes some practice. When the scraper comes into the cut area the idea is to; tag them with the dozer blade or ‘push block’ while they are still moving. This minimizes the impact to the machine and the operator. If using a regular dozer blade? You need to watch the blade ‘corner bits’ around the scrapers rear tires, it’s easy to puncture one.
I will carry the blade high enough to catch the stinger of the scraper and let it slide up to the center of the blade. With practice you can hook up with very little felt impact… without slowing down or stopping. After the scraper is loaded the next scraper should be on the way to get loaded.
The dozer needs to be backing up as fast as possible to get in position to allow the next scraper to get in front of it. I have found this to be one of the most fun operations in mass excavation… making it all work like a clock would.
I am a proponent of loading scrapers downhill whenever possible and as steep as a dozer will back up in second gear. This makes the best utilization of gravity and machines weight… thereby making significantly more production gains than loading on flat or uphill grades. The machines will not be worked as hard either… this matters in very hot conditions and terrain that is hard on tires and grousers on the dozer. It may require more ‘pioneering’ work for the dozer to set this up, or double and triple cutting a small stretch with the scrapers, it can be done with a little planning and ingenuity.
Making production rates can be achieved in many cases by adding more scrapers and trucks… they will pay for themselves. If you start adding dozers, loaders or other support equipment; then you need to do a cost analysis to determine the feasibility.
The production rate is determined by the way the job was bid. The estimator/ project manager should know exactly how this was determined… although I have seen many jobs bid with a ‘SWAG’- scientific wild ass guess. They may make money if done by someone experienced, however it does not pass much information on to the field.
You have to take the amount of money allotted per cubic yard of material and add all your equipment and labor costs to see what your production rate needs to be. The tough part of this may be that: you can’t use the equipment you truly need or the production rate may not be achievable with the conditions on the ground. Many times managers without practical field experience have a hard time visualizing what the job will cost you if you don’t use the correct equipment, (instead of what the job was bid for) and the right techniques to get production loading.
If this has been interesting or helpful you could buy me a cup of coffee.