Page 44: of Maritime Reporter Magazine (July 15, 1985)

PROPULSION UPDATE

Wichmann Reports On First Year

Of WX28 Engine Operation

Cross section of Wichmann's WX28V engine.

A/S Wichmann of Norway reported the first

WX28, a V-8 heavy-fuel engine, passed its first 12 months of operation earlier this year. The engine, which has a maximum continuous rating of 3,000 hp at 600 rpm, has now logged a total of 7,000 operating hours on board the M/V Bom- meloy. In addition to the operation of the WX28 on board the Bommeloy, extensive heavy fuel tests have been carried out on a 4-cylinder

WX28 engine on a testbed.

The operation of these two engines has demonstrated that the WX28 satisfies the heavy demands and stresses placed on the engine. The prototype V-8 on board the Bommeloy has not had any unanticipated breakdowns during its first year of operation.

An inspection performed on the valveless-tur- bocharged-medium-speed engine revealed prac- tically no cylinder wear. Clean ports and a clean combustion chamber indicated effective scav- enging and combustion. The heavy fuel tests on the 4-cylinder WX28L4 show cylinder wear well below 0.02 mm per 1,000 operating hours, a wear giving a liner lifetime of a minimum of 40,000 hours.

The WX28 has a cast iron piston skirt with a steel piston crown. The skirt is equipped with a shrunk-on bronze sleeve. Bronze is an excellent bearing material, and the piston skirts look new after one year of operation. The piston crowns have hardened ring grooves, and the groove height was well within the tolerances for a new crown.

The piston is equipped with three compres- sion rings at the upper end of the piston. Ring

No. 1 is a plasma-free-rotating ring, No. 2, a chrome-plated-free-rotating ring, and No. 3, a fixed-cast iron ring with a special gas-tight joint.

The ring grooves were clean upon inspection, and there was no fouling. The ring wear on the

V-8 on board the Bommeloy was so minor accu- rate estimates on ring lifetime are not possible.

Heavy fuel tests on the L4 indicate, however, an interval of 8,000 operating hours between ring renewals.

The oil scraper ring is located at the bottom end of the piston and is working below the ports in the cylinder liner, where the liner has no wear.

No wear was observed on these rings.

The engine has separate cylinder lubrication from a hydraulically operated cylinder lubrica- tor. The lubricator is essential in reducing cylin- der and ring wear, as well as keeping them in excellent condition.

The WX28 differs from earlier Wichmann engines with regard to the auxiliary blower. The engine has a fan (radial compressor) operated hydraulically with oil from the engine's lubricat- ing oil system. Hydraulic operation allows the blower speed independence of engine speed, which gives greater flexibility for adjustments.

The system has worked well and has proved reli- able and simple.

The turbo charger, main bearings, cylinder cover and fuel injection systems have all been functioning excellently, both on the V-8 aboard the Bommeloy and on the L4 on the test stand.

According to Wichmann, the first year of operation of the WX28 has been a success. The

V-engine has had several operating profiles con- ducted, with periods of full power, part load and frequent maneuvering. No problems have been reported of any kind, and inspection of the cylinders and the pistons show a clean engine with optimal conditions in both the cylinder and the combustion chamber.

For further information, including a complete detail-filled brochure,

Circle 51 on Reader Service Card

Monarch Introduces

New Pistol Grip

Portable Tachometer

Monarch Instrument of Amherst, N.H. has introduced a new convenient non-contact op- tical tachometer that is packaged in a pistol grip configuration. The new instrument, called

PHASAR-TACH, measures rotational speed over the range of 50 to 20,000 rpm to an accuracy of +/ -1 rpm. Speeds are measured by aiming the instrument at a single reflective marker on the rotating object and reading the displayed speed directly in rpm. Speeds can be measured at distances up to three feet and angles up to 45 degrees from the reflective target.

Two models of PHASAR-TACH are avail- able, the PHASAR-LCD featuring a liquid crys- tal display, both equipped with an on-target indicator. Both models are powered by four "AA" batteries accessible by lifting the hinged top cover of the instrument.

For those applications where the operator needs both hands free, PHASAR-TACH may be latched in the 'on' mode by means of a locking push button on the pistol grip trigger, and mounted on a standard '/J-20 threaded bushing at the base of the handle.

For more information on the new pistol grip tachometer from Monarch Instrument,

Circle 53 on Reader Service Card

Hydraulic Governor Valve Control

Surpasses Initial Expectations

A year after its introduction by the Power

Division of the Skinner Engine Company, Erie,

Pa., the first hydraulically actuated governor valve control for controlling steam turbine speed has performed even better than initial expecta- tions. Data gathered from dozens of installations around the country reveal a record of unsur- passed economy, adaptability and dependabili- ty.

The Skinner SPR™System—powered by the

Woodward TG-13 constant speed governor— requires fewer adjustments following initial start-up than comparable governor valve con- trols because it is a closed system with no mechanical wear points. It instantly corrects variations in pre-set turbine speed without the "hunting" for correct speed found in standard mechanical linkage controls.

The SPR system is free from the shock loads and backlashes which can cause the levers, arms and pins of mechanical systems to weaken or break prematurely. The system's elimination of speed correction turbulence also helps extend the life of the governor valve, cage and stem, and the absence of any mechanical linkage reduces maintenance costs.

At slight underspeed or overspeed conditions, the movement of a rotary actuator in the SPR system initiates a chain of events in the hydrau- lic system which opens or closes the steam inlet to provide immediate response to speed varia- tions. The Skinner SPR system also produces a substantial increase in the power available at the governor valve.

The Skinner Engine Company's SPR™System is said to be the first hydraulically actuated governor valve control for steam turbines.

The Skinner SPR system is a retrofit package made for all popular types of single stage steam turbines. It is presently available in configura- tions for Coppus, Elliot and Terry turbines with others available upon application.

For more information and free literature on

Skinner's SPR system,

Circle 52 on Reader Service Card 46 Maritime Reporter/Engineering News