Steam Engine Victor Maxi Twin

Krick Victor Maxi Twin steam engine with horizontal boiler

The Krick Victor Maxi Twin is a complete live-steam system for larger model ships with twin-screw propulsion. Two separate steam engines are supplied by a shared horizontal boiler and can be controlled independently of one another. This allows the speed and direction of rotation of both propellers to be controlled separately – an important prerequisite for true-to-scale manoeuvres on tugs, workboats and larger historic steamships.

The system is designed for model ships weighing up to approximately 20 kg. Krick recommends the Victor Maxi Twin, amongst other things, as a steam drive for the twin-screw version of the harbour tug Imara, whose model displacement is around 19 kg.

Two independently controllable steam engines

The key difference from the standard Victor lies in the twin-propulsion system. The Victor Maxi Twin features two separate engines, both supplied with steam from a shared boiler system. Each engine has its own control system for forward and reverse operation, as well as speed control.

This allows both ship’s shafts to be operated independently of one another. With the appropriate RC control system, for example, one shaft can be run forwards whilst the other is run backwards. This significantly improves manoeuvrability, particularly on tugs and workboats, and enables manoeuvres that closely resemble those of a real twin-screw vessel.

The shaft spacing can be adjusted between 50 and 110 mm. This allows the system to be adapted to different hull and shaft configurations.

High-performance system for large model ships

With a recommended model weight of up to approximately 20 kg, the Victor Maxi Twin is designed for large and heavy displacement models. It is particularly suitable for models where, in addition to sufficient propulsion power, a realistic engine system and separate control of both propellers are required.

The combination with the harbour tug Imara, which is expressly recommended by Krick, illustrates the typical area of application for this system. As a twin-screw model, the Imara has a displacement of approximately 19 kg and is listed by Krick specifically with the Victor Maxi Twin as a possible steam propulsion option. For steam operation, counter-rotating brass propellers with a diameter of 75 mm are recommended.

Horizontal boiler for installation in the ship’s hull

The horizontally arranged steam boiler has a diameter of 105 mm. The boiler base plate is 275 mm long; the overall width of the system ranges between 190 and 250 mm, depending on the set shaft spacing. The total height is approximately 270 mm.

The horizontal design distributes the weight relatively evenly across the engine room. However, as a complete system has a net weight of around 3.8 kg, its installation must be taken into account right from the planning stage of the model ship.

In addition to the sheer space required, the position of the two ship’s shafts, the gas tank, access to the burner and fittings, and sufficient space for maintenance work are particularly crucial.

Fully assembled and tested real-steam system

The Victor Maxi Twin is supplied as a largely ready-to-operate engine and boiler system. The engines and boiler are fully assembled and painted, and are tested and adjusted prior to delivery.

The scope of supply includes, amongst other things, the steam engines with adjustable oilers and reversing valves, the steam boiler with safety valve, water level gauge, pressure gauge and steam shut-off valve, as well as the funnel, gas burner and exhaust steam condenser. Planking strips for the decorative cladding of the boiler are also included.

This eliminates the need to build the actual steam engine from scratch. However, installation, gas supply, remote control, the shafting system and regular maintenance remain typical tasks associated with the challenging hobby of building full-scale steam-powered model ships.

Exhaust steam condenser for clean operation

The system includes an exhaust steam condenser. This captures some of the oil-laden exhaust steam and condensate escaping from the engines before it is discharged via the funnel.

This is particularly useful in a twin-engine system, as two engines produce a correspondingly greater volume of exhaust steam. At the same time, a condenser reduces oil and condensate residues in the model and helps to keep the engine room clean.

However, the tank should be installed in an easily accessible location, as it needs to be checked and emptied regularly.

Powerful twin-screw propulsion and practical application

The Victor Maxi Twin is designed not only as a visually impressive live-steam system, but also as a fully-fledged propulsion system for large twin-screw model ships. The separate control of both engines allows for different speeds and directions of rotation on port and starboard sides. This enables particularly precise manoeuvring of tugs and workboats.

Careful installation is crucial for reliable operation. Both engine shafts should be aligned as precisely as possible with the respective ship’s shafts to avoid placing unnecessary strain on couplings and bearings. The adjustable shaft spacing of 50 to 110 mm makes it easier to adapt to different hull designs.

Experience with Victor steam systems generally shows that sufficient space in the engine room and good accessibility during maintenance and operation offer considerable advantages. On larger steamships, the power reserve of this engine family is particularly well regarded. The Maxi Twin also features the more complex twin-engine system, which is why the burner, oil injector, reversing valves, condenser and boiler fittings should not be fitted too closely together.

Robust oscillating steam engines

Both engines operate on the principle of the oscillating steam engine. During operation, the respective cylinder swings slightly around its bearing, thereby simultaneously taking over part of the steam control.

This design does not require a complex external valve control system and has comparatively few moving parts. For model shipbuilding, this offers several advantages:

robust mechanical construction
comparatively low maintenance requirements
reliable operation at low speeds
good start-up performance
compact design
visible and true-to-prototype engine movement
easy reversal of rotation direction via the reversing valve

Particularly in the case of open engine rooms or removable superstructures, the working twin engine itself becomes an important visual feature of the model.

Lubrication and maintenance

Adequate steam lubrication is essential for reliable operation. Both engines are fitted with adjustable oilers through which lubricating oil suitable for steam is supplied.

Only steam engine oil or superheated steam oil may be used. Conventional machine, engine or bicycle oil is not suitable due to the temperatures reached during steam operation. Krick specifically recommends steam engine oil, item no. 60100, for this purpose.

In addition to lubrication, the boiler, safety valve, water level gauge, gas pipes, burner and all screw connections should be checked regularly.

Suitable for tugs and large displacement models

The Victor Maxi Twin is particularly suitable for large models that feature a genuine twin-screw propulsion system or where such a system is to be replicated.

Typical applications include:

harbour tugs
Ocean-going tugs
Workboats
Historical steamships
Passenger and cargo ships
Larger launches
Home-built models with two propeller shafts

A particularly good example is the Imara harbour tug on a scale of 1:32. The model has two propellers, just like the original, and is specifically recommended by Krick for use with the Victor Maxi Twin.

Essential accessories

The following are also required for full operation:

Krick 22314 Large gas tank, Ø 70 mm, with reheating
Krick 60105 Propane/butane gas cartridge
Krick 22316 Gas filling adapter
Krick 60100 Steam engine oil, 50 ml

These items are not included with the Victor Maxi Twin and must be ordered separately.

Contents

2 steam engines
adjustable oilers
changeover valves for forward/reverse travel and speed control
horizontal steam boiler
safety valve
water level gauge
pressure gauge
steam shut-off valve
Chimney with exhaust pipe
Gas burner with pipework
Exhaust steam condenser
Panelling strips for the boiler casing

The engine and boiler assembly is supplied fully assembled and painted.

Technical specifications

Length of boiler base plate: 275 mm
Overall width: 190–250 mm
Boiler diameter: 105 mm
Boiler height: 145 mm
Overall height: 270 mm
Weight: approx. 3,800 g
Shaft diameter: 4 mm
Shaft height: 12 mm
Shaft spacing: adjustable from 50–110 mm
Recommended model weight: up to approx. 20 kg