Rope pumps can be driven by low-speed electric motors or diesel and gasoline ("petrol") engines. Similar to the hand Rope pump, the discharge level of the water can be 1 to 5 meter above ground level if combined with a post and extra wheel.
New motor Rope pumps (Bomegas 2) can elevate directly without the need for an extra post.

Bomegas1 Motorized Rope pump in San Benito (Nicaragua) used for irrigation.	Bomelec Rope pump with electric motor, well 34 meter.

How it works

The basic elements of the Rope pump are an endless rope with conical pistons placed at intervals of 1 meter. The rope with pistons is pulled through a PVC raising main tube to lift the water to the surface.
The wheel and handle are made of galvanized tube. Spokes that clamp cut-out parts of a car tire, form a perfect pulley.
The pistons are made locally of rubber from cartires of high density polyethylene and fit with a small clearance in the rising main tube to avoid hydraulic losses. The rope with pistons turns around at the bottom of the well by means of a concrete guide blox with an internal ceramic or glass piece to reduce wear at this point.

Characteristics:

Advantages of Rope pumps compared to Piston pumps:

Technical advantages

• Absence of dynamic forces (rotating movement).
• Pump tubes can be made of light weight, cheap PVC tubing (pressure = distance between 2 pistons).
• Small diameter PVC tubing because of high water velocity.
• A high total efficiency, 80 - 85% if well made.
• Technology without "black box" (easy to understand, produce and maintain).

Social, economic and gender aspects

• The Rope pump requires regular maintenance but because of its simplicity and low cost the users can do the repairs themselves. No need for extensive training or manuals.
• Produced with local skills and materials.
• Supply of spare parts guaranteed (local production).
• Stimulates local industry generating work /income for small-scale enterprises. *
• Attractive as a household pump, because of its low cost.
• As a household/garden pump it generates income of US$ 220 per annum. **
• A household pump improves situation of women and children.
• Safes work. Income generated by a pump benefits the women and is invested in utensils, children education etc. Men often have "different priorities".
• Facilitates activities such as hygiene education, water conservation, reforestation etc. Since the Rope pump is useful / generates income, its introduction can be combined with above mentioned activities.
• Self respect/ educational. People feel proud that they can manage and repair the pump which sometimes is the "most technical" product in the house.

Disadvantages of Rope pumps compared to Piston pumps

• The Rope pump is not a "pressure pump" The maximum lift is determined by the height of the wheel axle, normally some 60 cm above the well cover. For higher lifts, an additional wheel is needed.
• Especially from deep wells, it takes some time before the Rope pump starts pumping. (When not in use, the water level in the pump falls back to the water level in the well).
   

  Bomegas 2 Rope pump with 1 HP gasoline engine, well 22 meter.	Round storage tank with a Nica-drip low pressure irrigation system.

Low-cost irrigation

Rope pumps can be combined with low-cost drip irrigation such as the Nica-drip This technology is based on the drum kit as promoted by IDE (International Development Enterprises). See www.ideorg.org.
The Nica-drip is being tested in Nicaragua by CESADE, FAO and AMEC.
 

An example

Irrigating 1000 tomato plants for US$ 120
Including: Pump, storage, irrigation system.

Rope pump
The pump capacity of a Hand Rope pump from a 10m. deep well is 2.4 m3/hour Pumping ½ hour in the morning and evening gives water to irrigate 1000 tomato plants. The Rope pump Pi model, can directly fill a water storage tank.

Storage tank made of cement
Instead of a metal drum, a cement tank may be used with the advantage of lower cost and no corrosion. The volume can be 500 to ..5000 liters, the lower part can be used for some fish production, and the tank can be constructed with local materials and skills. After a short training, users can make the tank themselves. The tank is round and reinforced with steel wire on the outside of the bricks. The filter for the outlet can be made out of PVC tubing. Instead of an outlet valve, PVC caps or tubes can be used

A cement tank of 800 liters consists of:
100 bricks, 1 kg of 1mm steel wire, 2 bags of cement, 6 bags of sand.

Nica-drip system
A water level in the tank of 0.5 meter is enough for the Nica-drip to function. A system to irrigate 1000 tomato plants consist of:

• 10 laterals of 30 m long with 1 mm holes at intervals of 0.3 meter
  (laterals are ½ inch hose, 15 mm inside, and made of black plastic)
• 1 Submain of 15 meter with 19 mm holes at intervals of 1 meter
  (submain are 1 ½ Inch hose 400 mm inside, and made of black plastic)

Instead of valves in the outlet, a "tube valve" can be used inside the tank.

Costs (based on cost in Nicaragua)

Hand Rope pump Model Pi (for wells 1 to 35 m.)       US$ 50

Storage tank 800 liters (material cost)                   US$ 30

Nica drip (material cost)                                      US$ 40

Total                                                              US$ 120

Dripper of the Nica-drip system.
Made of 2 pieces of hose, drip holes of 1 mm.                                                    

Technology transfer

The technology of the Nicaraguan hand Rope pump is being transferred to most countries in Central America and several countries in Africa and Asia. Of the wind Rope pump, demonstration models have been installed in 5 countries.

Experiences
Although the Rope pump technology seems (and is) simple, there are still many details in production, installation and use that can go wrong. There have been discouraging experiences with "just sending" drawings. Design changes were made, details in production and installation were not clear, etc. An example of this is the "Salvador case".
A Nicaraguan hand Rope pump was taken to El Salvador to be copied there. Without quality control 200 pumps were locally produced and installed. Because of an error in the guide box, most pumps broke down after a few months. Repairing these pumps and "repairing" the bad publicity of "another new technology that does not work", was much more expensive than a proper training in production etc would have been. (This does not mean that it is impossible to make the hand Rope pump, from written information but it proves to be cheaper if, from the beginning, proven and good quality Rope pumps are installed.)

Training
For a larger scale introduction, it is essential that local staff is trained on feasibility, preparation, production, installation and maintenance aspects. It is also needed to give long term "follow up" on aspects of use, quality control, marketing etc.

Training local staff in Guatemala in installing Rope pumps

Critical mass
Experience is that installing one or two demonstration pumps does not "automatically" start further dissemination. In order to interest future users, a certain critical mass of 5 to 10% of working examples in real field conditions is necessary and rather 10 pumps in one village than 1 pump in 10 villages. Regarding the production of Rope pumps, a certain "mass" production is necessary before it is cost efficient for a workshop or factory.
The involvement of the private sector in production , installation and service has proven to be essential for a successful and large scale dissemination.

Phased introduction
The introduction of the Rope pump technology should be phased depending on the model to be introduced. (For instance the wind Rope pump takes more time than the hand Rope pump)
Phase 1: Information/ basic study of the feasibility of the Rope pump.
First introduction and installation of 2 or more demonstration models. The complicated parts (washers, guide block) of the pump are transported from Nicaragua and the pumps will be mounted in a local workshop. *
Phase 2: If first experiences are positive, determine economic and social feasibility.
Training on production of a larger series using jigs / moulds, further training on installation and maintenance and quality control. For a successful introduction the publicity and marketing is an essential part.

. Source: http://www.ropepumps.org/English/motor.php