Why a feed tanker is not a standard truck wash
Feed residue is mostly dry and powdery on open surfaces, but it turns into a sticky paste wherever moisture reaches it: around a hatch seal, in a hinge, along a weld seam, in the sump of a rear discharge. That paste is the part a hose leaves behind, and it is also the part a buyer's customer complains about, because a leftover film of the previous load is what makes a following load off-spec.
Two practical consequences follow. First, a plan written for exterior paint and a chassis will leave the inside of the body, the door hardware and the discharge line untouched, which is exactly where carryover hides. Second, a plan that describes the inside only will miss the outside surfaces a farm visitor, an inspector or a delivery driver will judge the whole operation by. A defensible plan covers both sides and says which of them is being cleaned at which stop.
The outer shell: panels, ribs and frame
Tanker bodies are not smooth. Corrugations, stiffening ribs, mounting brackets, the saddle area and the chassis rails all hold dust, and the vertical rear face of a tipper or a live-load body holds more of it than the roof. The plan should name these by location, not say "body exterior", because a crew following the plan needs to know which features to aim at and which they can pass over.
Run-off from the outer shell has somewhere to go, and a plan that ignores it will fail an environmental check on site long before it fails a hygiene one. Where the wash happens, the plan should state how water is caught and where it goes. On a farm yard or at a mill this is often the binding constraint on the whole method, and it belongs in the plan before any equipment is discussed.
Hatches, manlids, seals and hinges
This is the area most often left out of a written plan and most often the source of carryover complaints. The rim around a manlid, the sealing face of a gasket, the clamp or cam-lock hardware, the hinge pin, and the channel a slide door runs in all collect dry feed, and every one of them is a place moisture can get behind. The plan should state, for each of them, what is checked between loads and what is taken apart on a longer cycle.
Seals and gaskets need their own line in the plan because they age differently from steel. Heat, detergents and repeated mechanical scrubbing all affect elastomers, and the effect is not always visible on day one. The plan should record what is done to them, how often, and what condition means replacement. Ask the equipment supplier, in writing, how their cleaning method interacts with the gasket material your body builder specified, and keep the answer with the plan.
The inside of the body: walls, floor, and the discharge path
For a tanker in feed service, the inside is the product-contact side, and the plan cannot be written by a wash crew alone. It has to come from whoever owns the feed-safety standard your customers audit you against, because the acceptable result, the evidence that must survive, and what counts as a failed clean are their call, not the operator's. What the cleaning plan then adds is the method, the sequence, and the check that proves the method was followed.
Break the inside into the parts that hold residue in a written order the crew follows: upper walls and the crown, the lower hopper or floor where material settles, the internal ribs or flighting, the discharge door and its seat, the discharge line or spout, and any hopper vent or dust filter. Dry bulk leaves a thin dust film everywhere, so the question a plan answers is not whether the visible load emptied, but where the invisible leftover sits after it emptied. On a tanker that carries several feed specifications in rotation, that list is the difference between a clean changeover and a claim.
Cab, chassis, wheels and the parts that are not the tank
The tractor unit, wheels, mudguards, steps and the underside of the chassis are a separate cleaning object and should be treated as one in the plan. They matter for roadworthiness and image, and on a biosecurity-minded site they matter because they move soil between premises. The plan should say which of these are cleaned at the wash point and which are only inspected there, so that "the truck was washed" does not quietly mean "the tank was hosed".
Engine bay and electrical areas deserve an explicit exclusion or an explicit method in the plan. Heat and water near wiring, sensors and intakes is a different job from cleaning steel, and if the plan does not say what is done there, somebody will eventually improvise. The fixed cleaning pages on the engine compartment steam cleaning listing name that task among the vehicle duties those pages describe; whether it suits your own unit is something to put to the supplier rather than infer from a listing.
Where the cleaning happens decides the shortlist
Most feed haulage operations clean in one of three places, and the plan should say which, because the areas a plan can cover follow from it. At the mill or depot the truck comes to a fixed point, so fixed installed equipment and a proper drainage route are available and the inside of the body can be worked properly. On the road or at a customer site the operation has to bring the equipment to the vehicle, and the plan can only promise what a mobile unit and whatever water is on site can deliver. A mixed pattern is normal; the mistake is a single plan that quietly assumes all three.
For the mobile case, PowerDe's mobile machines are described on their product pages as combining dry steam, wet steam and hot water in one unit and being built for indoor garages and narrow outdoor parking spaces, which is the shape of a depot yard rather than an open wash pad. Feed truck cleaning equipment on the cleaning equipment pages is the starting point to check against your own yard, water supply and drainage, and customized steam cleaning equipment is the route to raise a site-specific requirement when the standard pages do not fit it. Nothing on those pages claims a feed-tanker result, and the plan should treat suitability as something to prove on your own vehicle.
What each area needs written against it
A plan an auditor will accept holds the same few fields for every area it names: the area and its location on the vehicle; what residue is normally found there; the method and the order of work; what "clean" means for that area and who decides; what is inspected between loads and what on a longer cycle; and who signs it off. Areas cleaned between loads and areas cleaned weekly or per specification change should be marked as different, because a between-load routine is a carryover control, not a deep clean.
Two fields are usually missing from plans that fail, and both are cheap to add. One is the exclusion list: surfaces, seals, electrical parts and coatings that the method must not be applied to without written approval. The other is the trial record for anything new. Before a method is written into the plan as standard, run it on one tanker, one area at a time, and write down what happened to residue removal, to the seals and coatings, how long the job took, and how much water and run-off it produced. The trial sheet, not the brochure, is what makes the plan defensible afterwards.
Questions to put to the supplier before the plan is signed off
A short written list is worth more than a specification sheet. Ask what the equipment is actually supplied with and what must be bought separately; what temperature, pressure and water consumption the unit runs at on your site's supply rather than in a test room; what the method does to gasket material, paint, galvanising and any internal coating on your bodies; how the unit is sited, powered and connected in a yard like yours; what water and run-off it produces and how that is normally handled; and what training, spares and service support come with it.
Ask the same questions of every option you are considering, and put the answers in the same format. A cleaning plan for animal feed tankers earns its keep when a new driver can follow it, a customer can audit it, and a change of equipment can be argued from a written record instead of a memory of last year's trial.
