| It enables model U-boats (submarines) to use the static diving method up to a depth of 10 metres. The pump mechanism and the ballast tank form a compact unit, the so-called piston tank, often also simply referred to as ballast tank. |
A piston tank consists of a cylinder, a piston, a piston rod with thread, a motor with gears, levers as well as multiple end switches. By adjusting the piston in the cylinder, the water is sucked in or discharged, whereby the electric drive allows for a sensitive metering of the water quantity (filling volume).
Capacity The 750 System with 1.5 litres of total volume (consisting of 2 piston tanks with 750 ml each) is generally adequate for lifting models of up to 2 metres in length out of the water up to the waterline, so that an original looking image can be achieved.
For smaller models, the 500 System with 1 litre of total volume (consisting of 2 piston tanks with 500 ml each) is appropriate. For models with larger displacement, the 825 System with a total volume of 1.65 litres (2 piston tanks with 825 ml each) is available (only available as TA version).
In addition, piston tanks with a single volume of 250 ml to 1000 ml can be manufactured at the customer's request.
The relatively sizable volume of each piston tank causes a high level of buoyancy which, among other things, offers the advantage of a model being able to, for example, tear itself away with its own strength if it should become entangled with water plants and is subsequently able to resurface undamaged.
Furthermore, the large volume also allows for the mounting of mock-ups (such as a sea monster, shark fin or similar) or other auxiliary systems (e.g. underwater camera) on the hull.
In addition, diving systems with AutoTrim (type TA) allow simple "over trimming" which makes it possible to ground the model (park mode), whereby this position is limited in relation to the capacity of the receiver battery.
A decisive advantage of this diving technology is its highly reliable performance. The discharge pressure is sufficient for a diving depth of more than 20 meters and is therefore 10 times higher than is required for the normal operating depth of approximately 2 metres.
Within this operating range, only a slight demand is placed on the system, resulting in a very minimal use of electricity and yielding a high level of operational safety.
Moreover, since there are two independent piston tanks belonging to a system, a double safety factor exists.
A further considerable advantage is the system's insensitivity to pollution. Even when pure sludge is sucked in, the ballast tanks will continue to work trouble-free since everything that is sucked in is also discharged.
The entire system requires almost no maintenance. Servicing is limited to the occasional lubricating of the gears with a few drops of oil.
The operation of the system requires a hermetically sealed hull. Air displaced from the cylinder is compressed and stored within the hull so that excess pressure develops, which in turn causes increased compression strength of the hull's casing.
Since no venting and pressure equalization are required, no air exchange takes place and no water condensation can develop.
The switch unit in connection with a pressure switch form the heart of the diving system. The switch unit serves for the controlling of each ballast tank and also takes over the automatic emergency surfacing function as soon as the pressure switch determines that the model is sinking below its maximum operating depth of approx. 2 metres.
The pressure switch incorporates an additional safety function: As in the diving mode the ballast tanks are flooded (filled) the pressure within the pressure proof compartment inside the hull increases. If the pressure switch now senses a decrease of pressure within the hull resulting from a leakage, the diving mode is immediately stopped and the emerging mode is initiated.
Engel Diving Systems are available in the following versions:
Type EA with AutoStop
Type TA with AutoStop AND AutoTrim
Type TAE with AutoStop AND AutoTrimElectronic
Type TAES with AutoStop AND AutoTrimElectronic PLUS Static Depth Controller
Piston Tanks type EA are available in volumes of 500 and 750 ml each.
Piston Tanks type TA are available with volumes of 500, 750 and 825 ml each.
Diving Systems type EA in the standard version are equipped with an automatic end position shut-off, the so-called AutoStop device. This function is a part of the basic equipment of all Piston Tanks and respective Diving Systems. This device causes the timely shut-off of the motor of each Piston Tank mechanism as soon as the piston has reached its end position (i.e. cylinder fully filled or emptied).
Therefore, there is no rapid depletion of the motor battery and, moreover, no excessive strain on the motors and premature wearing out of the piston rod.
Piston Tanks type EA already come equipped with the necessary levers and micro switches.
There two alternatives to control the Piston Tanks type EA:
Switch Unit LPA (item-no. 1584-LPA) is an electro-mechanical, and therefore very reliable device for controlling 1 or 2 Piston Tanks. This unit is driven by a servo (not included) and comes complete with a pressure switch.
It electronic counterpart is called BTS (Ballast Tank Switch, item-no. 1584-BTS). The BTS offers up to 3 Fail Safe devices and works fully electronically, thus, no servo is required. The BTS is justed plugged into the receiver.
For models, such as Robbe's U47, the BTS combined with an Engel Piston Tank is the solution to convert this kit to a static diving model!
When ordering the BTS, the Pressure Switch (item-no. 5028) is an orption and must be ordered seperately if required.
All ballast tanks and respective diving systems are also available with the AutoTrim device. With this function, the model can be automatically brought into a state of perfect buoyancy under water and can be easily kept in this position without manual re-trimming. The AutoStop feature (automatic end position shut-off) remains a standard component of the AutoTrim device, so that this feature is completely sustained. Ballast tanks and diving systems that are ordered with the AutoTrim device come also already equipped with the necessary levers and micro switches. The switch unit LTA serves to drive and control the system. It is already included with the complete system type TA.
When operating an individual ballast tank type TA with only limited space available, however, we recommend to use Ballast Tank Switch BTS (item-no. 1584-BTS).
Diving systems with AutoTrim are now also available with an electronic switch unit (System Type TAE). This system works just like the normal TA version except that the control of the system takes place via a newly developed microprocessor controlled switch unit, whereby the control via a servo and micro switches on the switchboard is replaced. In addition, the TAE system incorporates a Fail Safe device which means, that the model emerges as soon as the R/C command is interrupted for longer than 4 or 7 seconds (adjustable).
The fourth system Type is called TAES which is based on the switch unit TAE but in addition, incorporates a pressure sensor. The sensor supports the boyancy control of the model and allows you to park the model at a depth of your choice (controlled via the transmitter). Please see section "Upgrade Kits" for further detail.
For the upgrading of diving systems or individual ballast tanks with the AutoTrim device, a corresponding upgrade kit is available. Please note, however, that only systems with AutoStop can be upgraded with the AutoTrim function. Older Systems that do not feature the AutoStop device cannot be upgraded (years 1979-1985).
System Type TAE can also be upgraded to TAES at a later stage (with upgrade kit item-no. 1585-taes).
Included in Delivery
A complete diving system consists of 2 piston tanks as well as the corresponding switch unit with all of the required components, including the pressure switch, connection leads and instructions for instalment and operation.
In the event that space allowance does not permit for the implementation of a complete system, only one ballast tank can be operated also - but only in combination with the appropriate switch unit. When ordering an individual piston tank the switch unit must be ordered separately.
Please note Operation without a completely connected switch unit will lead to damage of the ballast tank and consequently result in the total failure of the system.
Installation All ballast tanks and switch units, regardless of system type, are fully assembled and ready-to-run. Comprehensive instructions and wiring diagrams are included in order to connect the switch unit to the piston tank(s).
The diving systems including the ballast tanks and the switch units have passed rigorous quality and functional checks and comply with the CE standard.