Coal bunkers

[jran112]

In a large well ventilated fire The bunker would not be efficiently cooled by the sea water adjacent to hull The biggest insulator against the hull is the coal itself . Think of a boiler takes a lot of tube "area" to transfer the fire's heat to the water Coal is burned to hot gas with is then circulated
Now think of the coal in the bunker. The cold hull could keep the coal near it cooler but coal is a much better insulator then steel
the net result is a kind of "coking furnace" where volatiles are driven off the lower temperature coal near the steel wall and consumed in the fire .

Professor,

I understand this, and one point to probably discuss would be: If this fire was burning for several weeks before Titanic sailed as "experts" assume (I have never actually seen any proof of how long this fire was burning but maybe Sam or others has) and was so hot and hungry for fuel, wouldn't it be basically impossible for a few guys who are not professional firefighters, armed with some shovels, a few carts, and a water hose to extinguish the fire, wait for any residual volatile gasses/heat to dissipate, and then empty out presumably dozens of tons of coal or maybe hundreds in just a few days? They dont have protective/breathing equipment, probably very little/any training on how to supress fires, and very basic tools. The time frame just doesnt make sense unless the fire was tiny and easy to extinguish...

 

[Vincent Brannigan]

Here is what I am working on

Bunker Arrangements​

The arrangements in the Olympic and Titanic for loading and storing coal and feeding the coal to the stokeholds are the result of great experience. The bunkers consist of a ’tween deck space, on each side of the ship between the lower and middle decks, into which the coal is first shipped and from thence distributed into the cross bunkers extending the full width of the vessel in each boiler room. The stokers obtain the coal from doors in the cross bunker end bulkheads at the stokehold level immediately opposite the furnaces (see Plate VI.), an arrangement which reduces the amount of handling of the fuel for each boiler to a minimum. A further advantage of the bunker arrangement is that no watertight doors are required in the bunker ends, as each set of boilers has the necessary coal supply provided in the same watertight compartment, the watertight bulkheads dividing the boiler rooms being placed at the centre of the cross bunkers.


I cannot find any diagram of this " 'tween deck space"

 

[Robby House]

How far away? 10 feet?

There seems to be some confusion/questions as to how many hatch doors there were per coal bunker/stokehold facing each double sided scotch boiler. Some schematics I've seen would suggest there's a dedicated hatch door for each scotch boiler (meaning 5 hatch doors for Boiler Rooms 1-5, then 4 for Boiler Room 6 so in total there could be as many as 53 (5 single sided scotch boilers for BR1, 40 for BRs 2-5 with each containing 5 double sided scotch boilers and 8 for BR 6's four double sided scotch boilers). Other plans/computer renderings of Titanic's boiler rooms seem to show perhaps 4 hatch doors dedicated to a 5 boiler layout with 3 hatch doors for Boiler Room 6's 4 scotch boilers.

Regardless of how close or far these individual hatch doors were from each boiler the firemen that were assigned to each boiler half had plenty to deal with without worrying about fetching his own coal from whichever hatch door may or may not have been involved. Keeping each boiler's 3 furnaces adequately supplied with coal wasn't as simple as it may seem. Each scotch boiler's 3 furnaces had to be coaled at set intervals which was managed through the use of Kilroy's stoking indicators. Each furnace had an ashpit beneath the coal grate where the coals burned inside each furnace that had to be cleared out periodically and ejected outside vis-a-vis powerful ash ejection chutes. The job of a fireman wasn't simply shoveling a s~~~-ton of coal into each scotch boiler's 3 furnaces...there was a method to the madness as-it-were. As such steamers employed use of trimers to handle the job of extracting coal from the coal bunker's hatch doors, ensuring the coal was broken down into the right size, as well as ensure that coal usage was fairly even keel throughout the bunker or stokehold layout. Using too much coal on one side versus the other could actually produce a slight list for the liners which among other things reduced efficiency in the ship's propulsion, etc.

Below is one of the better cross sections of the boiler room layout to include details of the stokehold layout. Specifically between Boiler Rooms 6 and 5. The passageway between each Boiler Room on the Tank Top level effectively split each stokehold into with a Coal Bunker on each side of the passageway. Again, I'm not 100% on just how many hatch doors there were in each boiler room. The Harland & Wolf plans for Olympic don't seem to show that level of detail regarding the subject matter. Perhaps someone had knowledge of this information?

Hope this helps!

Robby
.

 

[Vincent Brannigan]

Trimmers removed the coal from the bunkers and and broke it up and delivered it to the stokers (firemen) The doors you describe are at the boiler level I am looking for trimmers hatches in F deck above the tween deck coal loading "platform" for want of a better word coal was dropped on the tween deck and distributed to the bunkers There must have been hatches in the F deck for trimmer access

I am using teh convention of Hatch for a horizontal opening and Door for a vertical one The coal came in through doal "ports" as in porthole"

 

[Robby House]

If Im not putting this in the right place, Im sorry. I just went Engine Stuff + Coal Bunker = Logic? Also, I looked up coal bunker on the search and nothing like this question came up.

Anyway, how the heck did the coal bunkers work? Was it just a giant storage room, full of coal, and whenever the stokers need coal they would get coal out of a little hole? Or was that "little hole" a dispenser with a button. What was it? How would they get the coal? What if the coal bunker ran out of coal?

Also, where the heck are the coal bunkers?

Here's the layout of Titanic's stokehold/coal bunker configuration for Boiler Rooms 6, 5, and half of 4. There is a stokehold dedicated to each working side of the scotch boiler layout. Each stokehold is further divided into coal bunkers, one on each side of the passageway that runs between each boiler room allowing crewmembers to easily access other boiler rooms or travel all the way back to the engine rooms, etc. Boiler Room 1 was the only Boiler Room that had single sided Scotch Boilers, so there was only one Stokehold for the first Boiler Room. The remaining 5 Boiler Rooms had 2 stokeholds each for a total of 4 Coal Bunkers that the trimmers accessed coal from through multiple hatch doors.

Technically there are more Coal Bunkers that are part of the stokehold system of each Boiler Room...however, in my way of thinking the ones that are at Tank Top level are the more important ones.

Hope this helps.
Robby

 

[Robby House]

I am working on a point involving the coal fire. I am Prof. Emeritus Fire Protection Engineering U of Maryland. I am a safety regulatory specialist with publications on carbon monoxide. My biggest problem with the bulkhead theory is the products of combustion /fire size issue. Everyone , including "fire and ice" focuses on temperature , which is meaningless. A match and a forest fire have the same temperature. references to temperature in reference to heating the water in the swimming pool are likewise meaningless.
The key issue is fire size which is measured in watts. (Or BTU/hr) Titanic's fire is an under ventilated smoldering coal fire in a closed steel compartment That means carbon monoxide as a fraction of combustion products is enormous.

That's whey they tell you a charcoal barbeque indoors can kill you quickly. Carbon monoxide is an odorless gas that causes thousands of deaths each year in North America. Breathing in carbon monoxide is very dangerous. It is the leading cause of poisoning death in the United States.

I have asked about the trimmers openings at the top of the bunkers and I have some measurements for the doors at the bottom. That is the air supply which determines the burning rate and heat output. in the normal case cold air would enter at the bottom and hot products of combustion vent out the top, unless the fire is of a near trivial size those products of combustion are lethal . If the trimmers openings at the top are closed the combustion gets more complex and the CO can go through the roof.
Yuan and Smith CO and CO2 emissions from spontaneous heating of coal under different ventilation rates
October 2011 International Journal of Coal Geology 88(1):24-30

Now if the fire is small enough and has enough air the CO itself can burn to CO2. Boilers are designed to make that happen Coal bunkers are not.
Coal bunkers are normally designed to feed coal by gravity to the access door so working the coal out did not require entering the bunker However if ther is a substantial concentration of carbon monoxide anyone near the door would be directly affected.

These all argue for a persistent but very small smouldering fire

Perhaps more importantly, Titanic's bulkheads, shell plating, and bunker partitions were made of mild steel. This is steel with little or no carbon content. Mild steel can be subjected to white hot temperatures and either quenched with cold water or allowed to return to room temperature slowly. It matters very little as the steel maintains its molecular integrity once room temperature returns to the steel. Now, with strong, high carbon steel...when its subjected to extreme temperatures...if it's quenched with cold water it becomes brittle...however if its annealed essentially put through a heat treatment process where the hot steel is allowed to cool a bit more slowly it maintains its strong makeup without becoming too brittle. There's essentially a tradeoff with high carbon steel that's been forged for whatever reason. Quickly quenching it with cold water makes it super hard, but also brittle. Allow it to cool slowly or in some controlled way (annealing) it will soften or at least not become super hard and brittle. If Titanic's hull and bulkheads were made of high carbon steel it would be subject to damage if exposed to high heat and not allowed to cool properly. I've read Fred Barrett's testimony (i think it was Barrett's) where he said cold water was sprayed on the opposite side of the bulkhead where the coal bunker fire was thought to have mainly existed (in the starboard side forward coal bunker of Boiler Room 5...so basically inside the aft starboard side coal bunker of Boiler Room 6. Of course the only way that would have been possible is if that coal bunker were also emptied of its coal. Who can say. But the point is with mild steel it's not as big a problem as it would have been with high carbo steel whether it reached white hot temperatures or not during the voyage. I firmly believe the angle regarding the coal bunker fire is much ado about nothing.

 

[Robby House]

Here is what I am working on​

​

Bunker Arrangements​

The arrangements in the Olympic and Titanic for loading and storing coal and feeding the coal to the stokeholds are the result of great experience. The bunkers consist of a ’tween deck space, on each side of the ship between the lower and middle decks, into which the coal is first shipped and from thence distributed into the cross bunkers extending the full width of the vessel in each boiler room. The stokers obtain the coal from doors in the cross bunker end bulkheads at the stokehold level immediately opposite the furnaces (see Plate VI.), an arrangement which reduces the amount of handling of the fuel for each boiler to a minimum. A further advantage of the bunker arrangement is that no watertight doors are required in the bunker ends, as each set of boilers has the necessary coal supply provided in the same watertight compartment, the watertight bulkheads dividing the boiler rooms being placed at the centre of the cross bunkers.


I cannot find any diagram of this " 'tween deck space"

Maybe this will help? It's pretty amazing!

 

[Robby House]

McCready, I've been trying to find this out myself.

The access could not be higher than G deck. F deck directly above contained places like the 3rd class dining saloon. There's no way a bunch of thilthy coal trimmers are going to climb all the way to E deck, then down into passenger dining spaces on F deck to open coal hatches onto G deck in the middle of breakfast.

At the highest, the access would have been through the fan rooms on F deck, which I think is unlikely. Perhaps there was an auxiliary access there for when the bunkers were truly full to the top (but I expect there was always a couple of feet between the ceiling and the coal.)

Access inside the bunker can also be ruled out. While there could easily have been a ladder inside for convenience, it couldn't have been the only access. While filling the bunkers, the trimmers would have been trapped at the top with no way down since the ladders would be covered in coal.

We also need to keep in mind that coal could be any level at any time, and require access. This means that access hatches must have been pretty high, and that there must have been some kind of ladder inside the bunker near those hatches.

We know there were catwalks in the boiler rooms, leading up through G deck level. Therefore, it's pretty certain that there were hatches from the catwalks on G deck inside the boiler room casings into the coal bunkers, where there were probably ladders.

This might help give a better mental picture of how the arrangement likely worked. From the Honor & Glory collaboration. Pretty neat!