Compact Urban Highways & Graffiti Steam Rig
Client: Metropolitan Borough Council & Public Works Department
155°C saturated wet steam single-axle rig for civic sanitation, graffiti removal, and chewing gum eradication without stone damage
Client Requirements
A metropolitan council needed an ultra-compact, agile mobile wash system capable of operating in pedestrianised high streets, historic civic squares, and narrow access lanes. The primary tasks included chewing gum removal, graffiti removal from sandstone and heritage brickwork, street furniture cleaning, and emergency cleaning of diesel spills on pedestrian paving. The system had to be legal to tow behind a standard municipal transit van without special heavy towing licenses.
Technical Constraints
Using conventional 250 Bar pressure washers on heritage masonry causes destructive surface erosion and mortar blowout. High-temperature saturated wet steam (150°C+) melts chewing gum and releases paint polymers thermally using very low water volume, preserving delicate brickwork while preventing excessive water pooling in public footpaths.
SYSTEM ARCHITECTURE & INNOVATIONS.
Alkota UK constructed a compact single-axle open rig powered by the Alkota 325-CSH steam generator with a Honda GX390 petrol engine. A 500L slimline baffled water tank provides up to 1.5 hours of continuous steam cleaning per fill. An onboard 12V battery charging system powers the diesel burner without requiring an auxiliary generator, keeping the unit whisper-quiet and lightweight.
Modulating steam valve generating 155°C wet vapour steam for chemical-free thermal degreasing
Slimline poly tank design keeping trailer overall width to 1,950mm for narrow urban cycleway access
Integrated WRAS Category 5 backflow air-gap system allowing direct connection to street hydrants
Chequerplate locking vault housing specialised steam nozzles, rotary surface heads, and safety PPE
Total wet weight of 1,120kg, comfortably towable by any standard municipal van
Subsystem Walkthrough
01 — High-Temperature Steam Generator
Alkota 325-CSH with specialised ceramic-packed down-draft coil producing true 155°C saturated wet steam at 172 Bar.
02 — Low-Width Slimline Reservoir
500L UV-stabilised tank with longitudinal anti-slosh baffles and integrated inline sediment filtration.
03 — CAT 5 Air Gap Break Tank
Complies with UK Water Supply Regulations 1999, preventing any possibility of contaminated backflow into drinking water mains.
04 — Telescopic Scene Lighting
Extendable LED mast powered from the Honda 12V charging circuit, illuminating night-shift graffiti removal in pedestrian precincts.
VERIFIED PROJECT SPECIFICATIONS.
Lifecycle Support & Maintenance
Like all Alkota UK bespoke builds, this system is supported by scheduled Planned Preventative Maintenance (PPM), annual IVA roadworthiness inspection certification, and our industry-leading 7-year hydro-insulated coil warranty.
Learn About Trailer PPM & Lifecycle Care →ENGINEER YOUR SYSTEM.
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