I wanted to start a new thread discussing the black smoke making of the USCGC
Itasca, at the invitation of Mr. Thomas. I read several comments in the Celestial Choir section regarding the black smoke the
Itasca made. These comments were made in links regarding navigation and would be better in its own thread in my opinion. For example:
https://tighar.org/smf/index.php/topic,383.msg5135/topicseen.html#msg5135I would caution anyone reading Mr. LaPook's comments regarding the naval rank of the source that the rank does not make one an expert. The fact that Mr. LaPook's source is an Admiral, while the other source is a Commander is not dispositive. The Navy has a lot of specialties, and it is not uncommon for someone of flag rank to be a specialist in only one area, but be in charge of matters that encompass other specialties. For example, the first commanding officer of our ship was a naval aviator, with experience flying the SH-3 Sea King. He had experience and technical ability regarding flying and anti-submarine warfare, but he was no expert when it came to running the ship's engines. I remember him coming down to the engine room on one occasion and remarking "These are dinosaur bones!" The distinction should really be based on whether or not the officer quoted as a source has experience as an Engineering Office of the Watch (EOOW) on a steam plant.
I served as an EOOW onboard the USS Duluth (LPD 6.) I was one of the few officers to qualify and actually stand watches. Many officers concentrated on other matters, and avoided the engine room at all costs.
The Duluth was equipped with two (2) Babcock & Wilcox 600 lb boilers. (The term 600 lb refers to the steam pressure, and not the weight of the boilers.) These were water tube, D type, meaning that the feedwater to be boiled into steam was inside the tubes, and the tubes were shaped in a backward capital D. There are other types of boilers, such as fire tube boilers, which means the fire is actually inside the tubes, and the water is outside in a drum. (I think the older rail locomotives used these.)
We produced fire for the boiler by burning DFM, which stood for Distillate Fuel Marine. Older fuel that had been phased out was called NSFO. I recall that NSFO was used from about World War II until the Vietnam era. Prior to World War II, the fuel was referred to as bunker oil. It was thick nasty stuff. One of my senior chiefs found an old publication that explained how to use the older fuel. It had to be heated first, and then atomized. When using DFM, we did not have to heat it, but we had to atomize it. (My chief drove that point home one day by putting a cigarette out in a can of the stuff.)
Our DFM was atomized using compressed air at light off. Once sufficient steam pressure was achieved, atomization was switched to steam, which atomized it and heated it. Each boiler had a furnace front containing 4 burners. The burner tubes were removable, and consisted of a tube within a tube. The inner tube contained the atomization source (such as air or steam) and the outer tube carried the fuel. The fuel and atomizer was sprayed through a burner tip which was inside the firebox, and sprayed it in a whirling pattern.
Fire was never sprayed against the tubes, but rather against the rear boiler refractory, surrounded by the tubes. Exhaust gases were vented out a stack.
The boilers were equipped with periscopes for the boiler technicians (BT's) to observe the quality of the combustion gases. Sometime in 1995, an electric stack gas analyzer was added while we were in the shipyard. This operated similar to an oxygen sensor on an automobile today. Obviously the
Itasca did not have a stack gas analyzer. As a back up, signalmen on the signal bridge (flag shack) were required to keep an eye on the type of smoke we were emitting.
Two types of smoke were of concern. The first type was white smoke. White smoke meant actual fuel was going up the stack and was an immediate emergency because it could explode in an atomized state and destroy the boiler and kill or injure personnel. White smoke generally meant too much fuel, not enough air. The signalmen had to be specially trained for this. That was because boiler safety valves and auxiliary steam exhaust also vented up the stack. It was not uncommon for a new signalmen to report in a panic that we were producing white smoke when it was just aux exhaust lazily venting to the sky.
Black smoke was the other concern. Generally black smoke was a result of low air feeding the boiler from the forced draft blowers. There were a variety of ways of producing black smoke (my guys could amaze me with their ability to get anything running in a weird way.) The main way was to swing the vanes with a louver from the air box into the burner front. (Like a set of venetian blinds.)
Black smoke was a concern for the following reasons:
1)
Damage: Black smoke meant that unburned fuel was building up on the tube sheets. While the BT's that worked for me did not like cleaning firesides, there was also a danger. DFM and other fuels contain sulfur, and we were always told that unburned fuel has a way of rapidly creating sulfuric acid at that temperature, very quickly. Sulfuric acid would rapidly corrode and eat at the tubes, which could lead to a loss of steam pressure, boiler damage, or even worse, a boiler explosion.
2)
Environmental: Obviously, this was not a concern in 1937. Today, however, the Navy is very uptight about the environmental damage it does, and there are laws governing what the Navy can and cannot do. Bilge water and oil must never be pumped over the side while in port, or a commanding officer can expect to get relieved. Sewage is never pumped over the side in port or immediately off the coast. Garbage must be weighted and dumped outside certain limits and it must never contain plastic. Air pollution is also a concern. Black smoke is very visible when a ship is in port, such as San Diego, and the Navy gets complaints and must cooperate with local air controls. I got some hell from our CO because my guys thought it would be cute to "smoke" the Golden Gate Bridge when leaving San Francisco.
3)
Economy: Making black smoke means the ship is not being run economically, because hydrocarbons are going up the stack and are wasted. More fuel has to be burned to make black smoke. Again, this is more of a concern today through the Navy's energy usage policies, but I imagine in 1937, the
Itasca would not want to be wasting too much fuel.
4)
Filth: Black smoke is filthy. When black smoke is being made, it tends to settle out over the ship, especially when the ship is not making way and generating apparent wind. The ship's deck force has to clean this up, and I've seen fist fights erupt over smoke made from our stacks. Looking at pictures of the
Itasca, I see that it was white. Black smoke falling on a white ship is a recipe for ugliness.
I must also point out that there is a difference between black smoke making and soot blowing. Mr. LaPook refers to soot blowing in several of his references. On board the Duluth, each boiler contained one soot blower assembly. The soot blower was a long pipe in one of the tube bundles, that could be cranked with a chain. When soot blowing was done, a valve was opened that admitted steam to the pipe. The pipe was rotated and steam sprayed from holes in the pipe to spray the boiler tubes.
Soot blowing was not done on every 4 hour watch. Soot blowing was never done in port, and for a very good reason that may be relevant to the
Itasca. Soot blowing requires a certain load on the boilers to ensure that the fires are not extinguished by the steam, and the ship must be moving through the water at a sufficient speed in a direction that causes the relative winds to carry the soot particles off the ship. Soot blowing always required permission from the Officer of the Deck, while underway, and was conducted once every 24 hours if operations permitted. (You never did soot blowing if the ship was engaged in flight operations, unless you wanted to end your career early.)
As I see it, the
Itasca was underway, but she was not making way. That meant that she was drifting to the side of Howland Island, and as the Officer of the Deck would notice her drifting on the current, he would order an ahead on the ship's engine telegraph to put the ship back in the area of where she was supposed to wait. Soot blowing would not have been permitted, or even used. But I can agree that there would be a limit to black smoking, to prevent damage, for economy, and to prevent filth in that position.