Saturday, 19 January 2013

Wartsila v/s MAN Marine Engines- Who’s is the best ?

         The stronger the marine engine, the better is the ship’s propulsion power and speed. When it comes to selecting marine engines for ships, there are only a few countable names in the market, including MAN B&W and Wartsila.In this article we are going to compare the two most powerful marine engine brands in the maritime industry.As discussed in one of our previous articles, the Most Popular Marine Propulsion Engines , MAN Diesel Turbo (previously known as MAN B&W) and Wartsila (Previously known as SULZER) are the two front-runner giants for supplying propulsion solution to the shipping industry.Wartsila & MAN both are in fact two rivals who have the best products and R&D in the industry. In this article, we will compare the different propulsion technologies provided by these two companies and will list out which technology has got the edge over the other.Note: This comparison is derived and compiled after taking views from professional marine engineers who have worked on both of these engines. However, this is not a yardstick for selecting marine engines for a ship.
Wartsila v/s MAN Marine Engines

Technology/ System
Wartsila SULZER
MAN Diesel Turbo
Who gets the EDGE?           
Intelligent Engine
RT Flex- A complete electronically controlled engine with common rail system
ME Engine- Complete electronically controlled engine integrated with hydraulic control.
Wartsila- For installing an Intelligent engine technology in 2001. Prior to MAN (2003).
Fuel Injection System
Common rail Electronic control with Delta Injection System
Hydraulic actuated Electronic Control Injection system
Wartsila- For integrating Delta control with 3 injectors controlled independently for different load.
Exhaust Valve Control
Electronically controlled variable exhaust valve timing
Camshaft operated Exhaust valve for reliable operation
MAN- For integrating a smart mechanical exhaust valve operation in Intelligent engine for reliable operation.
Fuel Injectors
Conventional fuel injectors
Zero Sac Volume type fuel injectors with slide valve
MAN- Slide type fuel injector reduces after burning and hence NOx emission
Fuel Pump
Spill, suction valve controlled pump with VIT
Jerk type plunger barrel controlled pump with Super VIT
MAN- Super VIT with independent injection timing control w.r.t fuel index.
Starting Air system
Starting air valve opened by 30 bar air and a closing supply for positive shut along with spring.
A relief valve in air manifold to avoid overpressure during starting airline explosion.
Starting air valve open by 30 bar air and shut by spring.
Bursting disc provided to avoid overpressure during explosion
Wartsila- Additional safety provided in positive closing and relief valve for reliability during manoeuvring.
Piston and Rings
Convex shaped piston with Jet Shaker cooling.
Chromium coated Piston ring.
OROS type Piston for better combustion area and reduction in piston temperature.
Controlled Pressure Relief type top piston ring.
MAN-With OROS piston, the Maximum piston temperature reduces by 90°C.
With CPR ring, better pressure distribution on liner and lower ring. 
Cylinder Liner
Fine honed and bore cooled Liner with mid layer insulation.
Bore cooled liner.
Wartsila- Better cooling and insulation increases Cylinder liner Life
Main Bearing
White metal bearing lined on thin back.
Tri metal bearing with high load carrying capacity.
MAN-Tri metal bearing with long life and better embed ability.
12-15 bar pressure from separate pump supplied to bigger size plain bearing.
Small size bearing with oil wedges to retain oil which is supplied by normal system pressure.
Wartsila-Elevated pressure ensures better lubrication at high load.
A back up line is provided in case of failure of crosshead pump. 
Cylinder Lubrication
Electronically controlled Pulse Lubrication System with metered quantity injection
Alpha Adaptive Cylinder Lubrication control system allowing blending of cylinder oil for different grade of sulphur in fuel
MAN- ACC with different inputs like sulphur content and load index provide better neutralizing features.
Gear driven with timing gear driving the camshaft
Chain driven with 2 chains driving a camshaft
MAN- Chain drives are cheaper, lighter and easier to maintain and duplication provides backup.
Prefers Axial turbocharger with constant pulse system.
Variable Turbine Angle turbocharger provides better operation at all load range
MAN-VTA allows engine to run without auxiliary blower at low load operation.
Exhaust Valve
Cobentional Valve seat with Nimonic and Stellite coating
W seat for better operation and increased time between overhaul.
Dura spindle with better heat resistant property.
MAN- W seat allows cooling of exhaust valve during combustion stroke
Tribo pack allows increased time between overhaul of cylinder component up to 3 years.
Electronic monitoring system for safe operation
Electronic monitoring system for safe operation.
Wartsila- With Tribo pack which is a package of design measures increases the TBO to 3 years.

 From the above comparison, it can be seen that MAN has 
an edges over Wartsila by a thin margins.
However, with the world’s most powerful marine engine (Wärtsilä RT-flex96C) in its basket, Wartsila is one company that doesn’t have to prove anything. 

Dear readers its just an study made under certain cases so there may be any tentative results......for more articles subscribe to my post.......