[handsofsteel]

Originally Posted by BlackBeard

"Soot blowing" is still done when the boiler is using fuel instead of gas but for safety reasons.

Efficiency is certainly an issue with the steam plant hence the shift to gas fired diesel engines with the advent in newer technology.

On the topic of Sootblowing.
It is actually a daily routine on dieso fired boilers and a 4-hrly routine on FFO fired ones(goes to show the difference between the quality of fuel ).

I merely illustrated it to highlight the rudimentary form of warfare those days which mandated abnormal combustion occasionally.

On efficiency
I intended to highlight the superior efficiency of the steam plant as none of the diesels / gas turbines that I've operated came close to this efficiency especially in transient operations. Is the efficiency of the gas fired diesel indeed more than 38%? If so, I'm really surprised (Maybe a feature of steady state operating conditions?)

[BlackBeard]

Originally Posted by handsofsteel

On efficiency
I intended to highlight the superior efficiency of the steam plant as none of the diesels / gas turbines that I've operated came close to this efficiency especially in transient operations. Is the efficiency of the gas fired diesel indeed more than 38%? If so, I'm really surprised (Maybe a feature of steady state operating conditions?)

Above is from an article regarding efficiency of the various propulsion systems in use on board LNG carriers. Hope it answers your query?

[handsofsteel]

Originally Posted by BlackBeard

Attachment 2587383

Above is from an article regarding efficiency of the various propulsion systems in use on board LNG carriers. Hope it answers your query?

I'm truly impressed.Slow Speed Diesels have come a long way. However, I suspect, these figures pertain only to steady speed operating conditions typical of commercial shipping and not transient conditions where, in my opinion, rotary machines will be more efficient than reciprocating. Further, at higher speeds, diesels are inherently inefficient. Let me delve deeper into this. Thanks for the information.

[sukhbirST]

Thanks for the interesting post. Being a Naval veteran, had the occasion to serve on many steam ships. Vikrant was one long experience. Amazing to have seen steam being used for everything. Sadly, last few years saw many accidents of steam leak but overall, it was good. The photos do not bring out the clear picture of working in these engine rooms which can be painful. Cleanliness is of course there. Only good thing was enough water for everyone which is still a luxury on other warships.

[Gansan]

Originally Posted by handsofsteel

1. The huge aircraft carriers (nuclear powered) are all basically steam driven with a closed loop steam system. Steam is generated in these using the energy from the reactor.

What about nuclear submarines? I read they too operate by steam turbines.

[cooldip]

Originally Posted by BlackBeard

Since there was interest shown towards this topic and there already exists threads on Marine Diesel Engines on the forum I am making one regarding the working of a Marine Steam turbine, YES they do still exist!

Originally Posted by BlackBeard

Some we remember for the others we have access to data from the ship & colleagues. There are more meticulous individuals who do maintain logs.

Originally Posted by Jeroen

I have my old seaman's book still. So I can always check names of ships and the period I sailed on them. Unfortunately, it is incomplete. I thought I lost it, so I got another one, which I lost as well. Only for the first one to turn up when I was cleaning up an old cupboard.

Thank you for all the details about the steam boilers and their internals. Having observed several ships during my time in Hong Kong, New York and London, I always thought that ships largely used heavy oil apart from the nuclear-powered military vessels.

Not related to the topic of steam boilers

I've always been in awe of the seamen's logs. I've tried adopting a similar approach in software engineering with very little success. I'm sure this process of logkeeping is a part of the marine engineering curriculum. Wish software engineering had an equivalent.

[Jeroen]

Originally Posted by handsofsteel

You probably did not consider warships while penning this down sir!
.

Yes, forgot about those. I’m merchant navy!

Originally Posted by Gansan

What about nuclear submarines? I read they too operate by steam turbines.

Yes, all nuclear marine propulsion is based on steam. Water (coolant) is circulated through the nuclear reactor at very high pressure. That high pressure, very hot water is circulated through a heat exchanger. The heat exchanger produces the steam which powers a turbine generator, which produces electricity which drive an e-motor that drives the propellor.

Or the turbine drives, through a gearbox, the propellor directly.



Jeroen

[BlackBeard]

Originally Posted by Jeroen

The heat exchanger produces the steam which powers a turbine generator, which produces electricity which drive an e-motor that drives the propellor.

Jeroen

On the newer LNG motor ships propulsion system is similar (DFDE & TDFE - Dual Fuel Diesel Electric & Tri Fuel Diesel Electric). The Gas Engine powers an alternator which turns the propeller via an electro motor.