On the request of the government, travel was made during this consultancy to the Shrimp and Milkfish Culture Applied Research and Training Project at Jepara, Central Java. The objective of the trip was to look into the equipment of the project specially the water pumps which are badly needed in pond production management for milkfish. It has been very desirable for sometime now to have these pumps installed because the region where the project is located has a narrow tidal range (2 meters annual absolute and 1 meter normal daily range). It should be noted however that while this survey was specifically made for the Jepara project, the observations and suggestions may also apply to other aquaculture projects. The pertinent observations and suggestions for this station are as follows:
(i) Water pumps. The project has an 8-inch pump driven by Yanmar Diesel engine. It also has portable individually powered gasoline pump units and a Unimog all-purpose truck with a pump.
The 8-inch pump came with Spicer shaft drive and an Amarillo right angle geared pump drive with 1:1 ratio for 1800 RPM. The RPM of the 8-inch pump is 1760 while the engine performance is 7 HP at 2200 RPM; 5 HP at 2000 RPM and 3 HP at 1800 RPM. Because the pump is on a 1:1 drive to the engine, the engine is naturally overloaded inspite of only 1.2 meter lift.
On receipt of the 8-inch pump at the Jepara project, it was decided to cut the Spicer drive assembly on the reasoning that the engine cannot or maybe too difficult to start with a load on it. Wooden pulleys were made at 1:1 ratio and flat belt drive was made with an idler drive also made of wood. The improvised modification did not work. After this it was attempted to put the Spicer drive shaft together again, this time with a GI pipe as shaft. The new assembly however could not be properly aligned and this new set-up did not also work.
To salvage the parts left of this equipment this consultant gathered the rest of the Spicer drive components and put up a shorter drive together. An elevated base for the engine was also put up. Care was taken in the process to have the shaft with as much correct alignment as possible so that it will work. Also, because the TDH where the pump is installed is only 1.2 meter less than 3 HP at 1760 RPM was hoped to suffice. In this case the pump can deliver close to full capacity but engine is still slightly overloaded. This pump setup can however be used until an engine with RPM lower than 1800 with about 10 HP (maximum advertised are at 7 BHP) can be acquired.
There is a definite need to see to it that the pump assembly and the engine to run it are well matched and such pumps are properly operated and maintained so that they can be effective tools for brackish water aquaculture management.
The idea of having heavy stationary pumps as well as smaller unit portable ones is advantageous for fishpond management. In areas such as Jepara where the tidal range is narrow a heavy stationary pump set-up at a strategic point along the perimeter of the experimental ponds can be very useful for proper water control and management. Such a pump set-up can be rigged with appropriate gate structures and pipe fittings and fixtures so that it can be used for obtaining water from outside or draining the pond system or part of it irrespective of the tide level, when desired (Figure 5a). The portable pumps can be used at specific areas within the pond system.
The same water problem is being encountered in the brackish water shrimp ponds in Thailand. Push or propeller type pumps are well developed and extensively used for these kind of projects in that country (Figure 5 b).
(ii) Equipment management - This station is well-provided with varied equipment and more are to come. These include, vehicles, pumps, various motors and engines, generators, electrical equipment, laboratory and field equipment, etc. There appears to be an urgent need for a technically trained staff to be stationed at the Jepara project to supervise the overall running of the Jepara physical plant and equipment.
The specific duties of this staff member will be to:
Work up an operational and maintenance log for every piece of equipment and try to implement it strictly.
Give advice on future procurements and give and screen all specifications relative to the equipment to be procured.
Decide what jobs can be done at the station shop and what must be sent out.
File and catalog all manuals and specifications and have these available whenever needed.
(iii) Assembling and overhauling of new engines - New engines, such as the Unimog Engine has been overhauled at the station apparently by personnel not familiar with this engine. As this is a costly piece of equipment it is suggested that the assembling be requested from the distributor's representative who would be knowledgeable of this engine. It was observed during the visit that the engine was down and the crankshaft ground down to 0.05 undersize. Subsequent to engine assembling, this equipment should have a regular maintenance schedule.
(iv) Yanmar generators - The project's two Yanmar generators are in need of major repairs. It is necessary to have these repaired properly so that they can be used to run the Roots blower in the event of power failure of the main generators. The engines of these generators can also be used to run the 8-inch propeller pump continuously and more efficiently as the BHP and RPM are close to ideal requirements of the 8" pump.
(v) Electrical load. There seems to be a need for an assessment of the total electric power requirements of the project. This should consider the needs of complete personnel complement as well as present appliances and future ones still to come. After this evaluation the circuit loads can be allotted and distributed properly. The present generated power at the project seems to be approaching total or 100% utilization. With planned new equipment requiring electric power it seems mandatory that a larger generating set should be procured shortly. The present largest generator set can be used as standby or emergency unit after it is reconditioned which seems to be necessary before any major breakdown occurs. There is also a need for a supplementary generating set as the one now being used is already inadequate in view of the added load due to increase in appliances in the staff homes and other continuous support facilities in laboratories.
FIGURE 5a
Push or Propeller Type Pump Used in Thailand
FIGURE 5b
DETAIL OF PUMPS,
GATE SET - UP
GOLDEN PALACE PONDS
SINGAPORE
NOTE: THIS GATE-PUMP SYSTEM MAY APPLY FOR ANY FISH FARM.
