Boiler and Engine Room Ballast Pumps

Stephen Carey

Stephen Carey

Member
Thanks for the reply. Most interesting. Yes everything I've read for the DC system aboard the the Olympic class ships used the ships hull/metal as the return leg. It's an economical solution. Would be so even today especially with the price of wire. I imagine when in the ship yards there were extention cords running everywhere for lights and tools. Same as a power plant during an outage. Temp power panels and cords everywhere. Potable generators too. I will have to go look up power ships. Never heard of them before. Sounds interesting. I don't remember the particulars but I was told that one of our aircraft carriers once backfed the grid to power a city during a grid failure. Think it was in WA or OR. Cheers.
DC went out years ago in favour of AC power. I have an old book somewhere that states "There is no conceivable use for alternating current power in ships" - a rather bold and inaccurate statement to be sure!
AC current calculations for the ampacity of cabling in a 3ph system means that just for starters you divide by root 3 (1.732) which almost halves the requirement bearing in mind standard cable sizes.
Whilst designing the electrical system for a couple of patrol craft for Bahamas Defence Force, the naval architects decided to shift the stern light from an upper deck to the stern and would that make a difference? The lights were powered from both AC and DC (warship standard) so had cables from each power source to the lights. The volt drop calculation for the AC lamp didn't warrant a change in cable size, but the DC one certainly did! Single wire and earth return as in my OP would cause all sorts of transients and eddy currents to eat your condenser and corrode anything not solidly earthed, and on a 3ph system using induction motors would be a disaster of course. As Titanic was largely steam powered apart from the stokehold fans and various other bibs and bobs I guess it was ok, but I would think subsequent ships were 2 wire.
I sailed on DC ships in my early days at sea and they weren't much different from the Olympic class other than being 2-wire. Brush and commutator open end generators, large open front switchboards made of slate and fitted with huge fuses and very satisfying hand breakers instead of a poxy button in modern ships! Got a photo somewhere of me standing beside one dreaming of Titanic...
 
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Stephen Carey

Stephen Carey

Member
Thanks for the reply. Most interesting. Yes everything I've read for the DC system aboard the the Olympic class ships used the ships hull/metal as the return leg. It's an economical solution. Would be so even today especially with the price of wire. I imagine when in the ship yards there were extention cords running everywhere for lights and tools. Same as a power plant during an outage. Temp power panels and cords everywhere. Potable generators too. I will have to go look up power ships. Never heard of them before. Sounds interesting. I don't remember the particulars but I was told that one of our aircraft carriers once backfed the grid to power a city during a grid failure. Think it was in WA or OR. Cheers.
Re Powershuos
Thanks for the reply. Most interesting. Yes everything I've read for the DC system aboard the the Olympic class ships used the ships hull/metal as the return leg. It's an economical solution. Would be so even today especially with the price of wire. I imagine when in the ship yards there were extention cords running everywhere for lights and tools. Same as a power plant during an outage. Temp power panels and cords everywhere. Potable generators too. I will have to go look up power ships. Never heard of them before. Sounds interesting. I don't remember the particulars but I was told that one of our aircraft carriers once backfed the grid to power a city during a grid failure. Think it was in WA or OR. Cheers.
Re powerships, here's a link. Karadeniz Holding
The one I surveyed for BV was their biggest at the time, in Medan Indonesia. Very impressive and their blurb guarantees a powership on site within 6 months.
All you have to do is supply them with gas or fuel oil.
The Medan one started on HFO until they got the gas line installed. Thereafter the company converted all the 34 or so MAN medium speed generators (fitted in what were the cargo holds of a large bulker) to run on gas with spark ignition rather than a diesel pilot burner. The last ones were being converted whilst I was there, with a few still running on HFO until they'd drained the fuel left on board.
 
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PeterChappell

Member
I suppose the important question is how much water could be pumped out of engine room 5 by all the pumps working together, since it is here that all the water would start to accumulate after the other forward compartments had overflowed over the bulkheads. Whilst this figure would be well below the minimum rate of flooding, this still affected how long the ship stayed afloat.

At an angle of 3 degrees, boiler room 3 pumps would have been about a metre and a half above boiler room 5, and the engine room pumps perhaps 3-5 metres (unfortunately the drawings have disappeared behind a paywall, so I'm working from memory). Although it would be of limited use for boiler room 6 pump to evacuate water from its own totally flooded compartment, could the valves be arranged so it was pumping water out of boiler room 5?
 
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Bill West

Member
Good morning, gents. In 2016 Karol W. posted a markup of the engine room bulkhead piping on the TRMA site. Karol, Ralph C. and I spent a few weeks trying to sort it all out. In the end we had flow chart style diagrams of the feedwater, steam and exhaust systems that looked fairly complete. I drafted the diagrams and that's what Stephen posted May 2nd. Thank you for preserving them and passing them on Stephen.

At the time I intended to also draw out the salt water systems but it dragged on. I was trying to do the whole tank top but found that the several systems overlapped enough to prevent easily seeing any one of them clearly. What I have done for now is extract the salt water systems for the engine room which with the 3 previous drawings at least completes that room.

TitnEngSalt


Bill
 
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Bill West

Member
This sketch is a simple version of the bilge and ballast systems. This is accurate about the number and location of the pumps but it is not so precise about connections. What it does do is give us a visualization that we can use to discuss ideas.

TitnBlgBal


I think a key confusion is that the various quotes about "all pumps connected" may only be in the context of "all pumps" in the bilge system are connected or "all pumps" in the ballast system are connected but the 2 systems themselves are not connected. The fact that 3 of the ballast pumps happen to have independent local bilge suctions doesn't help the quote writing either.

Miscellaneous points:
-could the attempt to rig a hose from BR5 aft be about trying to put the local bilge suction on BR3's ballast pump to work?

-pumping out the ballast tanks would help but wouldn't be fast enough and once the ship's head is down the suction pipes being at the aft end of each tank would limit the access to last third of the water.

-Peter's post #12 point about our 14.7 psi atmospheric air pressure only providing a 33' theoretical maximum seawater lift for a vacuum suction is relevant but the measuring point won't be the inlet of the suction pipe, it'll be the water surface above it. The head of water from the surface will push the water along the pipe until it gets back up to the surface level. As another consideration, a sample 600 long ton per hour flow through 200' of 10" steel pipe turns out to only be a 0.8 psi drop in pressure from the friction. So that aspect is not very important to the driving pressure.

Bill
 
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PeterChappell

Member
So would the maximum capacity of all the pumps for removing water (assuming the water was at a sufficient height) be 1200 + 250 = 1450 tons/hr assuming the water was at a sufficient height, and one of the ballast pumps was hitched up with the flexible tube? I recall there were no bilge or ballast pumps in BR4 according to the Titanic plans, is this incorrect? Where do the ash ejectors come into all this, could they have been used for bilge pumping in an emergency?
 
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Seumas

Seumas

Member
So would the maximum capacity of all the pumps for removing water (assuming the water was at a sufficient height) be 1200 + 250 = 1450 tons/hr assuming the water was at a sufficient height, and one of the ballast pumps was hitched up with the flexible tube? I recall there were no bilge or ballast pumps in BR4 according to the Titanic plans, is this incorrect? Where do the ash ejectors come into all this, could they have been used for bilge pumping in an emergency?
The ash ejectors could be used to pump water in an emergency but the impact would be minimal.
 
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Bill West

Member
Hi Peter.
Indeed with access to BR5's ballast pump flooded and BR2's too far away the total capacity to deal with the flooding would be 1250 tons of bilge pumps, plus BR3's 250 ton ballast pump if a hose was connected there. If the boiler room ballast tanks have been put into use to offset the coal consumption's lightening of the ship then that ballast could also be pumped out to give some buoyancy. But it would only be 2377+968 tons and the Engine Room + BR2 ballast pumps only add up to working on it at 750 tons/hour.

BR4 does have a bilge pump but it is on the starboard side, there is no ballast pump. The pump is on the ET deck plans but is hard to see right now with the zoom not working.

The ash ejector is a syphon powered by the bilge pump so it is not a separate source of pumping capacity. Its hopper sits over a discharge pipe with a nozzle in it and a 200psi jet of water sucks in the ash and blows it overboard. Verbal Notes & Sketches 1916 pg148
To use it for flooding:
-the room water level would have to be high enough to flow or leak freely into the hopper
-the pump capacity must not be slowed by working at the high end of its pressure range
-to be worthwhile the sum of the operating water and the sucked in water must be substantially greater than just running the pump as bilge alone

Bill
 
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khoi nguyen

Member
Hi,
I wonder if the bilge pumps of steam ships like the Titanic were kept warm by steam all the time, so that they could begin to pump out water at any time when needed. Or were they left cold and needed some time to warm up before they could work.
 
Mike Spooner

Mike Spooner

Member
Question: Was there any Board of Trade regulations on bilge pumps capacity?
 
Mike Spooner

Mike Spooner

Member
Hi Peter.
Indeed with access to BR5's ballast pump flooded and BR2's too far away the total capacity to deal with the flooding would be 1250 tons of bilge pumps, plus BR3's 250 ton ballast pump if a hose was connected there. If the boiler room ballast tanks have been put into use to offset the coal consumption's lightening of the ship then that ballast could also be pumped out to give some buoyancy. But it would only be 2377+968 tons and the Engine Room + BR2 ballast pumps only add up to working on it at 750 tons/hour.

BR4 does have a bilge pump but it is on the starboard side, there is no ballast pump. The pump is on the ET deck plans but is hard to see right now with the zoom not working.

The ash ejector is a syphon powered by the bilge pump so it is not a separate source of pumping capacity. Its hopper sits over a discharge pipe with a nozzle in it and a 200psi jet of water sucks in the ash and blows it overboard. Verbal Notes & Sketches 1916 pg148
To use it for flooding:
-the room water level would have to be high enough to flow or leak freely into the hopper
-the pump capacity must not be slowed by working at the high end of its pressure range
-to be worthwhile the sum of the operating water and the sucked in water must be substantially greater than just running the pump as bilge alone

Bill
Bill,
just a matter of interest I see you must have Verbal Notes and Sketches books, I have the 17th edition volumes 1&2. but it does not say what year published. As in my book the sketch drawing of the ash ejectors is on page C82. Is your the same in1916?
 
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Bill West

Member
Good evening Gents.

Khoi -steam pumps don't need a warm up. Operators of larger machines like locomotives or ship engines do open the cylinder drain cocks for a moment when starting to let out the condensation that occurs in the first few strokes but after that they are okay. For small engines like pumps this is just not worried about. I've run small steam pumps and the small amount of water that condenses in the first stroke or two seems to just get swept out with the exhaust. Besides the stroke speed and power are too low to break a cylinder head if there was a water lock. A locomotive could have the initial momentum of a train behind it if the cylinder had a water lock.

Mike
-BoT and pumps, I think there was a guideline but I can't put my finger on it right now. I think it was crude and perhaps related to warship guidelines. I think the Titanic's ballast pumping needs exceeded the guidelines anyway.

-Books, go to WorldCat.org, put "au:Sothern AND ti:Verbal notes and sketches" into the search bar and sort by Date(least recent). Notwithstanding typos, that will give the editions and years. HathiTrust and Archive.Org have 1916 and 1918 for free. The 17th edition is 1947. I have actual copies of Vol I 18th edition 1951 and Vol II 19th edition 1959 as well as files of the online ones. In 1951 I have See's ash ejector on page C90 and it has a few more words than page 148 in the 1916 edition but is essentially the same. As an aside, my mixed editions are a constant nuisance in going from the index to the pages because of the updated page numbering between them.

Bill
 
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Mike Spooner

Mike Spooner

Member
Bill, thanks for the reply.
I have that feeling that the BoT never set a bilge capacity flow rate for commercial ships of over 10,000gtr. Like so many other regulations too.
That the Titanic did exceed the BoT regs for bilge pumps.
 
Mike Spooner

Mike Spooner

Member
When the Olympic was withdrawn from service and returned back to H&W Belfast. One of the improvements mentions is her bilge pumps capacity was increase. Do we know how much by? As quote for Titanic 1,700 tons per hour. But as for Aquitania the same size ship two years later on is 4,500 tons per hour by use seven ash pots per boiler room.
The question I ask: Had the BoT change the rules on expelling water from below the water line?
 
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