Used Machinery Review: Caterpillar 815F soil compactor

By: Ron Horner

Presented by
  • Earthmovers & Exacavators

In the earthmoving world the humble soil compactor can be the least loved of jobs on site. However, says Ron Horner, get behind a Caterpillar 815F and you might enjoy it more than you expect

Caterpillar-815-soil-compactor
Soil compactors – the glue that hold the dirt jobs together.

Buy now
Compare new


I’ve said it many times before but I defy anyone not to be mesmerised by the efficient running of an earthworks project when you have a fleet of scrapers, dozers, water trucks and compactors all working  together as a finely tuned team.

The speed and continuous movement of all the gear working in unison, carving up the landscape and creating a masterpiece before one’s eyes is truly breathtaking at times.

The co-ordinated approach to certain jobs has many aspects in making it a successful outcome and can vary depending on weather, planning, design, location, supervision, operator skills and the type of equipment sourced and used for the job.  

In this case I’ve chosen to look at the baby of the fleet and quite often the importance of this type of machine is totally overlooked – the humble Cat 815F soil compactor.

Caterpillar-815-soil-compactor
The all-round vision for the operator is perfect.

AROUND THE MACHINE

At first glance, one would think it’s a reject after a sexual encounter between a front-end loader and a pad foot roller.

Built like a Rugby Union front row forward – short squat and solid as the proverbial – sitting on a set of solid steel wheels covered in hundreds of steel tips and with a blade attached to the front, just to make the uninitiated think a bit longer before making a comment.

For those of us whom have operated, worked beside or been responsible for the maintenance and repairs of this machine we know just how efficient these compactors are, and they are a must for every small and mid-sized earthmoving contractor.

These are the glue that hold the dirt jobs together, for without efficient compaction tools such as the 815F and the talented operators that handle them, most of the jobs would be a failure.

Caterpillar-815-soil-compactor
The 815F’s wheel/tip design ensures a perfect compaction outcome on most soil jobs.

ON THE JOB

The 815F is specifically designed for heavy-duty compacting operations and just thrive in these conditions encountered onsite.

What makes this machine so efficient is the design of the tamping wheels and tips, which have a modified chevron pattern offering greater penetration and compaction for high production. This design also makes for cleaning of the wheels so much easier when moving the machine to a new job, but to my mind it’s the design of the tips that make this machine my favourite.

Not too much unlike a conventional "sheep’s foot" roller or a "pad foot" roller in design, this design allows the compaction tips to ease their way into the soil, compact over a greater surface area and ease their way out of the compacted materials. You get equal compaction in forward or reverse as the wheel/tip design has 12 tips around the wheel in five rows in width and sitting at approximately 200mm high and 150mm wide ensures a perfect compaction outcome on most soil jobs.

Others similar type machines have their own tip design issues like being too square or too long from wheel to end of the tip. In some cases these can pick up the material and clog the void between the wheel and tip, affecting the efficiency of compaction and making cleaning the wheels a chore in itself, and they can also rip the compacted materials out of the ground as the wheels rotate, making the compaction programme a drawn-out affair.

The wheel design has you covering the whole four wheel width coverage in just two passes with front and rear wheel tracking that eliminates gaps and overlaps.

Caterpillar has nailed it with this design.

The accolades do not stop here as, in my opinion, the tilt blade is perfectly designed to push and trim with minimal effort on the machine.

Caterpillar-815-soil-compactor
Ron appreciating the blade design.

Some people don’t appreciate the design of a blade, whether fitted to a dozer, excavator, grader or compactor, but believe me, it’s the money-making end of the machine.

The 815F compactor certainly takes a bit of moving with all 240 wheel tips creating a significant amount of drag but I just love the design of this blade and it works a dream in these conditions.

Compaction is achieved from bottom of the lift to the top and is designed to condition, spread and compact the soil layers below the one currently working. If the conditions are dry you could require the support of a water truck (not needed if the soil is at optimum moisture). If you get some good scraper operators and good communication system in place, working these jobs are just the best to view from an elevated position.

The operator-friendly controls and the articulation of this machine certainly make it one of my favourites for comfort, vision, efficiency and production in what is often considered a rubbish job on most sites.

The job may not be the most exciting, like the adrenalin rush of running the dozer or scrapers, but running a compactor is the best grounding a young operator could ever wish for when starting out, as they won’t have too much competition amongst the crew and will learn the hard way the best way of moving, conditioning and compacting the dirt, but more importantly they will learn "why" this has to be achieved as well as "how".

Caterpillar-815-soil-compactor
With a big armchair, operator-friendly controls, A/C and radio, it’s a comfortable cab for the driver.

IN THE CAB

First thing you notice is that the all-round vision for the operator is perfect. With a reversing camera top right of screen, great dash layout, mirrors perfectly located and plenty of glass on all sides, the operator has all the basics to have a good day at the office.

Cat seating has always been up there with the best and this is no different. Adjustable steering wheel, quick gear kick up/down button for speed of gear changing, Power Shift transmission with three forward and three reverse gears (steering consul mounted) with push forward or backwards for direction and twist grip for gear changes.

The 815F can get to almost 18kph forward and an impressive 20kph heading back to the crib shed for lunch or knock-off.

The blade control is on the right of the big armchair seating, totally self-explanatory and operator-friendly to use and the A/C and radio makes for a perfect setting for a long day.

Caterpillar-815-soil-compactor
The metal engine enclosures are hinged, which allows for easy access and inspection.

UNDER THE HOOD

Running Cat’s C9 ACERT six cylinder turbo charged diesel engine, pushing out 232hp (173kW) is what gets the beast up and running in the morning and runs like clockwork.

Getting to some parts of the engine bay is a bit of a hassle due to the size and location of wheels to access the engine, but it’s a breeze to access the engine bay from other points.

The metal engine enclosures are hinged, which allows for easy access and inspection. The lower left hand rear side is positioned nice and low to enable access to the oil filter, grease points, air filter, power train oil dipstick, coolant sight gauge and high speed engine oil filler.

On the rear of the machine the radiator/oil cooler and air conditioner condenser are accessed by the swing-hinged cover, however on the right side of the machine the ground access is limited due to the wheel positioning. To check the fuel filter, water separator and engine oil dipstick you can stand on the wheel scraper bar to give you that little bit of extra height for those of us who suffer from short man syndrome.

Running costs for such a machine can be allocated to several areas, including fuel (450-litre tank) and you will use it all in a big day as it pushes the 20 ton rig through the soft material.

Other areas of cost are maintenance and timely replacement of the ground engaging parts such as blade cutting edges, wheel tips (200 on machine) and daily servicing costs.

I’ve had the pleasure of owning a couple of Cat compactors (Not F Models) and found that they can be a costly item to repair if you fail to see the signs of oil leaks, especially in the drive wheel hubs.

I remember that bill very well but really pales into insignificance in the large scale of work we achieved with these units.

Caterpillar-815-soil-compactor
The 815F is well balanced and efficient to use.

IT’S A WRAP

Caterpillar has a couple of models of compactors, such as the 815, 825 and 835, and they are designed to suit varying materials and project scopes.

A specialised piece of earthmoving machinery (which in many cases would not be in use all day every day), but when the time comes get the old girl out and you have to brush off the spider webs there is no better machine to take up the challenge than this.

An expensive purchase item for the smaller contractor to undertake, many earthmoving contractors take the opportunity to source one such type unit form a reputable hire company such as Sherrin Rentals in Brisbane.

The Caterpillar 815F is the perfect machine for projects such as this one run by Danny Hope of Hope Civil in SE Qld, complementing his fleet of scrapers and dozers and adding the glue to seal the job together and I love it.

RELATED ARTICLE

Vintage machines

You can also follow our updates by liking us on Facebook