How to operate a self-loading mixer: the cycle in order

The daily pre-start check belongs in the plant's own manual, which we neither hold nor publish. What we can tell you is what is on board to be checked, and it is not the same on every model. Four of the six mixers published here state a fuel-tank volume: 100 litres on one, 120 litres on two, 135 litres on one. The hydraulic system holds 100 litres on three of them; on the fourth the plant's English and Chinese sheets give different figures, so we state none. Engine oil is 16 litres on one and 20 litres on three. Electrical starting is two 12-volt batteries on four models, 60 amp-hours on three of them and 100 amp-hours on the fourth. Two of the six publish none of those figures, and on those two the quantities have to come from the unit's own sheet before anyone opens a drum of oil.

Two checks deserve naming because they are easy to assume. Braking is described in full on three of the six: a butterfly service brake and an emergency brake acting on all four wheels, with a separate double parking brake. The other three split three ways. On one we hold no sheet, and nothing on its equipment list names a brake at all. On another the equipment list names twin brake callipers and stops there. On the third the English and Chinese sheets describe two different braking systems, so we state neither. Automatic lubrication is standard on exactly one of the sixteen mixers in our records and optional on four more of the published six — and on the model where it is standard it appears on that model's option list as well, so what is actually fitted is settled by the unit's own paperwork rather than by the range.

The first half of this step is fixed by the machine and the second half is not. All six published mixers carry the same verified loading method — a self-loading bucket — so the sequence starts with the machine driving at the pile rather than with a wheel loader filling it. Steering is where the models separate. Four of the six carry articulated steering on their equipment list, and three of those four also carry it as a verified specification. On the fifth, the plant's English and Chinese sheets contradict each other — one says front-wheel steering, the other articulated — so the specification row is withheld, although that model's equipment list still carries the English reading. The sixth names no steering type at all. Which layout a machine has changes how it is lined up on a stockpile and reversed out of one, so it belongs in writing before a machine is chosen for a tight yard.

Whether the machine weighs what goes into the drum decides how this step is actually performed, and the answer is model by model rather than categorical. An electronic hydraulic weighing system is standard on exactly one of the sixteen mixers in our records. It appears on the published option list of four more of the six, which means a machine of that line can be quoted with it or without it. The sixth model's list does not mention weighing anywhere; in that position it names a high-definition LCD driving display, and a display is not a load cell. On the one model where weighing is standard, its option list carries it as well: the same contradiction the lubrication system carries, and the same answer, which is the document issued for the specific unit. With a weighing system the operator charges to a target and the batch leaves a record. Without one, the batch is what the bucket brought.

Water is added at the work front, by the operator, which is the whole convenience of the machine and also the step at which a mix can be spoiled after it has been batched. Two arrangements exist across our records. Seven of the sixteen mixers pair an automatic water-fill controller with an external suction pump, so the machine draws its own water from whatever the site has — a bowser, a standpipe, a pond. Eight mixers of the other product line instead carry a high-capacity water tank with a self-priming system and name no external pump. Of the six models published here, five have the first arrangement and one has the second. The distinction is worth raising before it is discovered on a job with no mains supply, because one description is about drawing from an outside source and the other is about carrying and priming.

What no record states is how much water the machine carries. The water-tank capacity is unverified on all six published models, and the five plant specification sheets we hold give fuel-tank, hydraulic-system and engine-oil volumes with no water field on any of them. So the question of how many batches the machine mixes before it has to go and find water again cannot be answered from the paper we hold, and anyone quoting a litre figure for on-board water is quoting something our sheets do not contain. Cement is the same kind of open question: a cement hopper appears on the published option list of five models and on no standard list at all, so how cement reaches the drum is settled model by model, in the order, before the first shift rather than during it.

The drum turns while the machine drives, which is why mixing and travelling to the pour are one movement rather than two jobs. The only mixing figure in our records is the drum speed: 16 revolutions per minute, stated on four of the six published models and identical on all five plant specification sheets we hold. Travel speed is recorded on four models — 0 to 23 km/h on one and 0 to 36 km/h on three — and these are declared maxima, not a speed for a charged drum on a site road. Five of the six models carry a verified statement that the drum lifts and rotates through 270°, so the drum can be raised and turned with the machine standing still. One of the sixteen mixers is a distinct build whose list states that the drum holds its mixing direction while the machine travels, and it is not among the models published here.

No mixing time exists anywhere in our data. How long, or how many revolutions, a batch must turn before it is placed is set by the mix design and the specifier, not by a machine data sheet, and we will not supply a number for it. Nor does any of the sixteen mixers in our records list a revolution counter or a mixing timer, so on the machines we document that count is not something the cab displays — it is the operator's own reckoning against the drum speed, or it is the specification's, checked at the pour. The same applies to output: no verified figure for cubic metres per hour exists on any of the six published models, so this page states none. What a machine actually places in a day is set as much by haul distance and pour access as by the machine itself.

Discharge is aimed by moving the drum rather than by repositioning the machine, and that is what the 270° figure buys on the five models that state it: the drum lifts and turns, so the discharge point is chosen from the cab instead of by driving round to a new angle. One of the sixteen mixers describes its bucket as front-load, rear-discharge. Five of the six published models carry a discharge figure, and they run from 1.0 m³ on the smallest to 4.0–4.5 m³ on the largest; the sixth has no discharge figure we are willing to publish, because its English and Chinese sheets give different ones. That figure is the volume of mixed concrete the machine produces in a batch. How many batches your pour needs is arithmetic on your own drawing, and we do not do it for you.

Washout is the part of the cycle that moves with the machine. Because the concrete is mixed at the pour rather than delivered to it, the drum is washed out wherever the work finished, and the containment problem a batching plant would have handled is now on your site. The United States Environmental Protection Agency's fact sheet on concrete washout puts the chemistry plainly: washout water is a slurry containing toxic metals, "caustic and corrosive, having a pH near 12", and its stated best-practice objective is to collect and retain all the washout water and solids in leak-proof containers. The chemistry travels; the legal obligation is local, and it is yours. On the equipment side, five published models carry the external suction pump as standard and all five list a high-pressure wash-down pump as an option rather than as standard. The sixth lists neither.

We do not publish an operator manual, and nothing above is one. Torque figures, service intervals, running-in procedure, fluid specifications beyond the capacities listed, fault codes and the sequence for a safe tow all belong in the document the plant issues with the unit. Whether that document is issued, and in which languages, is something we confirm in writing before shipment rather than assume, because in Russia and Kazakhstan a Russian-language operating manual is a mandatory import document and not a courtesy. We hold no copy of one for any model on this site. What we will do is ask for the configuration list, the option list and the specification sheet for the exact unit quoted, in writing, and pass on what arrives. What we will not do is close a gap with a figure taken from a similar machine.