Diggers / Excavators

Basically we can break this down fairly simply into two categories, tracked & wheeled.







Tracked machines have the ability to rotate 360 degrees around their tracks, usually referred to as an ?t machine, also known varying as mini / midi - diggers, diggers or 360's. Interchangeable buckets often with quickhitches, can be fitted with hydraulic breakers (peckers / hammers) grapples and grabs.

One key thing to remember is that if you slew through 180 degrees the track levers reverse, for example if the dozer blade is in front you push the track levers forward to move forward. If you rotate the cab so the dozer blade is now behind you and push the levers the chassis will still move forwards but you will be travelling backwards.

The other thing to watch out for is that the left hand control arm tilts out of the way on most machines, some start with it up, some start with it down. When the arm is not locked down the two joysticks and usually the track levers become inactive. On the bigger machines with more space in the cab the arm is fixed, but there is a separate lever that folds up or down to isolate the controls.

The controls in this (cramped) cab give you some idea of what to expect.

The left hand joystick controls the slew of cab, and the dipper arm in and out. The red lever is the safety lever that must be locked down for the controls to work. On the floor is a foot pedal, which on this machine would operate a hydraulic breaker if fitted.

The right hand joystick controls the curl of the bucket (crowding the hitch) and the main jib up and down. The foot pedal would operate the offset boom (see below). The knob next to the armrest raises and lowers the dozer blade and the grey box operates the quick hitch.

In the middle are the track levers, with fold out foot pedals so you can move it and operate the 2 joysticks. As the machine is now with the blade in front, you would push the levers to move forwards.

This is a hydrualic quickhitch it grabs the bucket and can be operated from inside the cab.



This is the offset boom joint, it allows the boom to work at angles to the cab making it handy to get into awkward places. This can be handy on a zero tail swing machine because you can rotate the cab through 90 degrees to the tracks and fold the boom in and use less floor space on the truck bed.




My final advice on moving diggers / excavators is to watch the weights, they are generally referred to as an 8t machine or whatever. That could actually be a 7.5 or 8.5t weight. This weight can be sometimes found on a stamped factory plate.



but bear in mind that will be the basic machine with no quickhitch or buckets and no fuel either. Realistically it's going to weigh a bit more depending on machine size. If you are unsure of the actual weight it's usually possible to identify the weight bracket the machine comes under by the model number ie. PC27 = 3t Zx50 = 5t / JS 130 = 13t

Just to illustrate this point, the picture below shows two machines loaded, a Hitachi ZX50 on the front and a Yanmar 75 on the back. By the numbers that's 12.5t however once the buckets, quickhitches and fuel are added in they actually weighed 14660Kg. I loaded this at a quarry and noted the GVW on my way out. It was 25960Kg!





Wheeled diggers, are your stereotypical JCB properly known as a backhoe loader (American terminology) quite simply because the bit that digs is the backhoe and it's got a loader (big scoopy bucket) on the front.



Mini diggers







Typically anything 3t or under. Rubber tracks often no full cab some tiny 0.75t & 1t machines have no cab at all just a folding rollbar so they can be taken inside properties. Usually 1.5t is the smallest used, 3t also popular for little jobs like building extensions. Dozer blade on the front. Controlled by two track levers for moving the machine around the site, and two joysticks that control the main boom / jib, dipper arm, tipping link, slewing and occaisionally the offset (more usually a fot pedal). Basically nearly everything that's not on the chassis of the machine. The two joystick control system is fundamentally the same regardless of machine.

Midi Diggers



These machines are 5t - 8t in size and are bigger more powerful versions of the above, 5t machines generally on rubber tracks, some 8 tonners running on steel. Often fitted with a quickhitch which allows the buckets to be easily interchanged, hydraulic quickhitches allow the buckets to be changed without leaving the cab. On the bigger cabbed machines there's enough space on the roof to put a rack on to hold cabguards, make sure these are not loose and the lid is secured with something otherwise they fly out. Becoming more popular with Zero or Negative tail swing which means that the arse of the machine does not overhang the tracks when you slew round.

Excavators



Now getting to the big stuff, same as before just bigger. Steel tracks, but can be fitted with bolt on rubber pads for use on tarmac. 13 / 14 & 20 tonners most common as can be transported on a 44t lowloader. Bigger machines of 30t + will need STGO transport. 20 tonners running at over 11' wide so special rules apply for movements anyway. 13 / 14 tonners can be moved on a rigid although not common. I can just carry this JS130 if it has no buckets on (which is pointless) A slightly 6 wheeler might just manage but generally it'd be an 8 legger to do it.

Ducks



Basically a 360 machine on wheels, usually 13 -18t although a few smaller ones about too. Controls as per normal machines but with a steering wheel and pedals to move around, again the driving controls do not reverse when slewed through 180 degrees, turn left = steer right, to reverse = forward gear. Not too bad until you start shunting one to get in a space and you're the wrong way round. These machines are lowloader jobs as they are tall. Generally used on roadworks as they are a large powerful machine that is manouverable but won't chew the tarmac like a tracked machine.

Wheeled Diggers



Also sometimes referred to as a 180 as the back arm can dig a 180 degree radius. Most common machine is a JCB 3CX although there are Volvo, New Holland and a few others about too. Not as popular as in previous years although still a handy tool. Generally have a set of flips over forks on the front bucket. Taking a 3CX for example it has a nice big cab with a steering wheel and pedals, and torque converter type gearbox. Handbrake and front bucket levers usually found to the right hand side although some better specced machines have joystick controls on the armrests. The seat can be rotated to the rear to control the stabiliser legs and the back arm. These are a bit confusing as the joysticks move in an x rather than a + movement like on a 360. A 4CX like the one above has 4 big wheels and can steer 2 wheels, 4 wheels or crab steer.

These machines are awkward to secure as they generally have poor facilities to tie them down.

Most usually have some tie down eyes at the front underneath the loading bucket arms like this.



Otherwise I'd either chain across where the bucket meets the arms or strap over the front axles.

At the back they never seem to have tie down eyes (except for Volvo's) On a decent machine I usually pass a chain through the kingpin joint at the back and clamp it down really tight.




Older machines have a nasty habit of settling on the legs slightly and this will end up with a loose chain, on these I tend to use another chain across the feet and giving a backwards tow. As yet I've never lost one. It's worth checking the straps or chains after a short while if you are unsure,

I never leave the arm raised in the road travel position either as it makes the machine higher than need be, I tend to place the bucket at the foot of the beavertail with the knuckle between the ramps so that it cannot swing out in some freak accident.



Just a couple of pointers when loading them. Firstly take a look at the brake pedal, it's actually two pedals joined by a little connector. If the catch is open you can brake the left or right side independantly. Make sure that it is shut and the two pedals act as one, as I nearly lost one when I hit the brakes and got it at about a 30 degree angle. I couldn;t work it out until I was told about the split pedal.