Many times construction business owners are faced with the dilemma of choosing between an articulated truck and an excavator or even a wheel tractor scraper. What you end up choosing mainly depends on the unique fill and cut conditions present at the jobsite. There are a number of jobsite factors that need to be considered. We look at a few below and how they influence your decision.
Type of material is the most important
The very first thing you ought to look at is the type of material that you’re dealing with. There are certain materials that are best moved using an articulated truck or a scraper. The ideal time to use a scraper would be when you need to load materials that spread easily. They are great at moving sandy loam soil. Also, scrapers are the cheapest way to move dirt and they are quick under the right conditions. That said the biggest problems with scrapers are that they are not as tolerant when the dirt or mud is wet, sticky or rocky.
Articulated trucks are not easily constrained by the type of material that is loaded on to them. At times you can carry semi liquid, and even sludge consistency material using a tailgate.
Changing weather conditions
Changes in the weather can dramatically alter the conditions at the job site. The best all weather earthmoving system is the articulated truck which works all year round. However, scrapers are limited to just dry weather conditions. When things get wet and slippery the scraper will not work.
Vertical and horizontal cut
The overall depth and the length of a machine’s cut will have an effect on how it performs. This is regardless of if it’s a scraper or an articulated truck. As a rule of thumb it takes around 100ft to 300ft of dirt to load a scraper, so if the cut is 100ft then it is more difficult to load. On the other hand articulated haulers are not easily constrained by space. This is thanks to their loading methodology, haulers can be placed under the excavator in the tightest spaces. It takes a lot more room for a scraper to operate as compared to excavators and articulated trucks. So, scrapers are best for work that is laid out in a large circuit.
Haul roads also influence choice
Both scrapers as well as articulated trucks tend to work great on smooth haul roads. So, none of the two options have a major advantage over the other. However, twin engine scrapers do consume a lot more fuel, so if you have a rather long and high speed haul the conventional twin engine scraper will end up costing you a lot more in terms of fuel and so is uneconomical. On the other hand if the haul road is rough then it favors articulated trucks.
The grade of a haul road will also influence what you choose. Twin engine scrapers as well as articulated trucks both can easily handle steep grades with articulated trucks having a slightly better advantage. Single engine scraper will take very long to go up a steep grade haul road making them inefficient.
Scraper operators need to have years of experience in order to operate a scraper properly. The spinning of tires by an inexperienced scraper operator can cause damage to the machine. Also, the availability of old school scraper operators are too few because running a scraper requires talent. On the other hand articulated trucks are much easier to operate. But with both good training is required something that is a big necessity with scrapers.
Trucks are more versatile
Articulated trucks and excavators work much better in tandem and are easier to own pieces of machinery. Scrapers are only good for loading, scraping and dumping. An excavator can be taken to most job sites, and they can move a lot more dirt.
The pull type scrapers
Over the past three or four years the pull type scraper has become increasingly popular because they are relatively inexpensive, plus they move earth in a more economical fashion. That said there are limitations to this machine, the materials it can haul are limited to what a towed scraper can haul. So, if anything they are best suited for light stripping of the top soil. Which happens to be a pretty common earth moving job these days?
Mark has been an earthmoving machine operator for thirty years. Today he owns his own earth moving and construction business based in Sydney.