Spiral pump (coil pump)

Passive

A coil of pipe wound round a wheel that turns in a stream. Each rotation scoops a slug of air and a slug of water into the outer end of the coil, and the chain of them pushes water out of the centre and up a delivery pipe. No valves, no seals and nothing that has to snap shut, which is what separates it from the ram pump: the ram is loud and lives on a shock wave, this turns slowly and quietly. Lifts less than a ram for the same fall, and needs a current to turn the wheel rather than simply a head of water.

One of 10 ways to meet Sourcing / extraction. Build 2/10, Upkeep 3/10, Efficiency not rated. Cost, carbon and footprint below are rated against those 10, not in absolute terms.

Cost: Low
Upkeep: Seasonal
Skill to build: Intermediate
Lifespan: Long; the coil outlives the bearings, and the bearings are the serviceable part
Embodied carbon: Low
Space / material use: Low
Output timing: Continuous process
Skill to repair: Basic
Regulation (FR example): Abstraction from and works within a watercourse are regulated; a declaration or authorisation is normally required.

What your site needs

A watercourse with enough current to turn a paddle wheel

Inputs

Flowing Water (Hydro Potential)

Outputs

Unheated Water

Ranking in its sub-function out of 10 alternatives

Every option in this sub-function, with the value on each axis and a note on what drives it (this solution highlighted):

Solution	Build skill	Upkeep burden	Efficiency
Drilled well	Intermediate	5	N/A
Rainwater harvesting and storage	Basic	3	N/A
Spring capture	Basic	2	N/A
Manual/hand-operated well pump	Basic	2	N/A
Rope pump (manual, low-cost well pump)	Basic	2	N/A
Hydraulic ram pump (belier hydraulique)	Basic	2	N/A
Fog collector (cloud net)	Basic	2	N/A
Mains water connection	Specialist	3	N/A
Free-standing rainwater catchment	Basic	4	N/A
Spiral pump (coil pump)	Intermediate	4	N/A

Build skill and upkeep burden are proxies (lower burden = simpler to maintain); the efficiency column is this sub-function’s ranking, 1 = best. “N/A” where an axis isn’t rated here.

Sources

Building and running a spiral pump, with dimensions and performance

Tutorials

http://lurkertech.com/chris/eco/pump/tailer/

What this page does not tell you

No sizing or quantities: how much a technique yields, and how much a household needs, both depend on the build and the people, so the catalogue compares options rather than dimensioning them. It carries no bill of materials and no build sequence, and it is written for an oceanic, clay-soil climate (Normandy, France). Regulatory notes are indicative and need confirming locally.