Marine Engineering - Super Eco Speed

Replies

• 

  gohm

  Jolly,
  
  What makes you think the engines are not designed for manouvering speed? As long as minimum specs for the engine operation (lubrication, cooling, etc) are being met your biggest effect will be erduced wear & reduced fuel comsumption this of course assumes the fuel calculations have been done. however trip duration will be greatly increased and also have effects on hull maintenance. These costs could outweigh any savings from fuel & engine maintenance.
• 

  jolly

  What makes me think there may be problems with reduced speed is several factors.
  
  1) Those are the biggest engines in the world designed for continous speeds with load 60% to 100%. Running them below that rate and consequences may be costly.
  
  2) reaction of my chief engineers is not favourable one.
  
  3) Efforts from some makers to produce a kit to equip the engine for slower speeds. There must be a reason for this.
• 

  abhaysbhonge

  jolly

  Hello,
  
  I am a shipmaster, and during my carier tried to learn as much as possible about marine diesel engines, as this makes my life very much easier, and also easier for my chief engineers - by not putting them in impossible situations.
  In the recent world economic crises twe owners are putting shipmasters and vessels in new situation asking to reduce the speed for which the largest engines in the world have not been designed.
  The subsequent consequences for exploatation of such engines in such a way are not known.
  
  
  A question for marine engineers:
  Large container vsls designed for speeds of up to 25-26 knots, and B&W engines of 75.000 HP to 90.000 HP (10 or 12 cylinders).
  Max rpm 104 / 26 kts
  Eco rpm: 80-84 rpm / 20 kts
  The recent trend is to reduce speed to some 14 to 16 knots, which actually is manouvering speed. (60-65 rpm, with blowers running)
  
  The question:
  1. What is the long term effect on main engine?
  2. Once per day running on full navigation speed - can this help?
  3. Any other comment or advice.
  
  In case any additional info is needed, I will be very glad to post it.

  -The long term effect is definitely not good but as a immediate soultion to downturn in economy this is the best option.
  -Running once per day at full speed will definitely help to reduce the deposits as higer scavenger air pressure more than 1 bar is needed to blow off the deposits and left overs from the combustion.
  -The ships were designed with high speed and high power engines when the container market was booming and at peak. The situation is totally reveresed demanding reduced operating costs and this is the best way. This will allow ship owners to just manage to breakeven.