Ready for the USS Monitor's Steam Engine ? Part 2

[Rich_Carlstedt]

I've got to ask about the design, why? Was it the only way to fit the space, horsepower, or what that justified that design that I've not seen in anything else. It just seemed a rather complex way to make an engine.

You have to go back to that period of time and what was being done for marine engines. Basically there were 3 designs , Vertical engines , 2 cylinder "V" Oscillating engines, and Horizontal (mill style) engines. But before we review those,we must consider that the Monitor was a totally new ship design, as all the war ships those days were wooden frigates with iron sheets on their sides ( Thus the term "Ironclad" ) . The Monitor was really the first "Stealth" warship. The ship was only 10-1/2 feet tall ( w/o Turret) and drew 9 feet of water. The propeller was 9 feet in Diameter, and this meant that the engine crank Center Line was at 4-1/2 feet above the keel. The engine could be no more than 4-1/2 feet above that in the engine room , which immediately ruled out Vertical and oscillating styles and forced the designer to a horizontal mode. But that was a problem as horizontal engines had to be mounted 90 degrees to the propeller shaft ( Called athwartship) and that required a very wide ship ( Beam) and the Monitor was narrow and shallow by design .
Now Horizontal engines mounted athwartship have the cylinder one one side ( say Left) and the crank on the other (Right) and the crank should match the propeller C/L making them extremely wide , but they did have second cranks on some called back-acting engines where the power is transferred back to Propeller C/L .....even the Monitors engine does that. But what John Ericsson did was put the cylinders (2) together in the center of the ship --Go here to see his 1858 ( pre Monitor design ) engine in action .. note the "back acting"connecting rods turning the propeller shaft ( very short videos )
http://www.stationarysteam.com/linked/p ... y_2-10.mp4

Now that engine was still too wide, so he went to a Trunk Design which is seen here in the next link
Only half the engine is shown , but it is a cutaway to see the trunk design, and this is exactly scaled - note size of the 9' propeller
http://www.stationarysteam.com/linked/r ... rom_sw.mp4

The cylinders were 40 bore with a 22 inch stroke and ideal for the Monitor, which is not only the first all steel warship but very low in the water so it is hard for the enemy to hit .. There are over 40 inventions in that ship. and John Ericsson gave them all to the US Gov.
Rich

[Mr Ron]

Your workmanship is fantastic. The drawings you made were equally well done. The details were superb. I could never build a model of the engine as my skill would never be good enough.

[kcameron]

Rich,

Thanks for documenting why this engine was needed. I hadn't considered the size of the prop. Now the design makes a lot more sense. Hope to see it again at Cabin Fever next year. I presume you also had some data about the boiler that needed to fit into the limited space too. I hadn't considered that the whole space was as shallow as it was. They could barely stand up below deck. Just thinking about how they stoked the fire.

[BClemens]

Technology previous to the civil war was mainly mechanical and was busting at its seams. The engineering and scope of manufacture was, and is still flabbergasting to this day. There was no CAD and certainly no CAM so engineers were sleeves rolled up manual workers with the foundrys and with machine shops and with assembly shops. Their dedication and their 'get-r-done' type attitude was also astounding especially with the fact that they were frantically aware of what was happening in the world at that time. My God! And we continue to do this to this day - with CAD/CAM and I have software that will find the trace paths for a circuit board for a schematic diagram for a fart sensor circuit to turn on a fan... and 'worse'.
A day at a time...God love and save us all!
BClemens

[Greg_Lewis]

...The engineering and scope of manufacture was, and is still flabbergasting to this day....

Some of the stationary engines made in that era ran for 100 years without being shut down for repairs. Maintenance yes, but broken, no.

[Steggy]

...the Monitor, which is not only the first all steel warship but very low in the water so it is hard for the enemy to hit ..

The Monitor could have done a lot of damage to the CSS Virginia had she (Monitor) been permitted to use more propellant in the guns. Despite Dahlgen's reputation in building naval cannon, the propellant charge was limited to 15 pounds, even though Monitor's guns could withstand the pressure of a much heavier charge (I dimly recall reading that Dahlgren's "soda bottle" design could easily tolerate a 25 pound charge). A heavier charge would have substantially increased muzzle velocity, which given the close range at which much of the Hampton Roads battle was fought, as well as Virginia's somewhat rickety construction, probably would have demolished the Confederate ship.

[pete]

I've got a book written about the naval weapons from the Civil War era Rich. While it covers the Dahlgrens used later on in the war, it doesn't say anything at all about the Monitors battle. And your 100% right, Dahlgren barrels were probably over built compared to any others. Even eyeball estimates from the first picture in this Wiki link shows that. https://en.wikipedia.org/wiki/Dahlgren_gun General practice at that time was government appointed inspectors would use very precise go/no go gauge balls for bore size, test firings would be made, and then what was called proof loads used. Afaik that always consisted of a double charge of the maximum that caliber was rated for of both powder and shot. Only when the gun passed those tests were the barrels stamped by those inspectors saying it was accepted. A few guns did blow up during those tests, and since the manufacturer's knew those proof loads would be used they were pretty careful about quality since they didn't get paid for anything that failed. So it's odd they forced them to back there powder loads off. That ship was very costly comparatively speaking against the conventional ships of that time and just about experimental in nature. A possible reason maybe? But interior and exterior ballistics was also far less well understood at the time and that would certainly be true for the Navy's top brass giving orders to the captains they had to follow.

[kcameron]

A thought about the powder limit on the guns, might it have been the magazine limit? If they could only hold X amount of powder and shot, and the captain thought he needed Y number of shot to win a battle, that might have meant the less ideal load for the gun. If they weren't thinking of the more powerful hit meaning you need way less, this could also have been an issue. If they were really cramped for space for the powder and shot, that might have been the limiting factor.

[Rich_Carlstedt]

BDD is right, a heavier charge would have decimated the Confederate ship, but there are several reasons they did not use more powder
But first, there was only one injury in the Monitor during the battle, the Captain was blinded when he was looking out a 1" slit in the iron and a Confederate shell exploded outside . The Virginia had 16 sailors injured in the battle from flying Oak Splinters. The Monitor had 8" of iron thickness on the turret and the Captains Wheel House. The Virginia had 3" of lapped iron on a sloped surface , so it represented about 5" of iron depth and that was backed up with 3 ( or 5 !) feet of solid white oak, but the concussion of Monitors hits actually exploded the Oak on the inside and caused those injuries.
The 11" cannon balls were Cast Iron and weighed around 170 pounds , but Ericsson had Forged Cannon balls made for the battle ( 240# ?) and on the ship, but the Navy brass did not want them used . The 11 inch guns were proofed at 50 # , and Ericsson wanted them to use 30 #, but instead they used 15 # of powder- later in the War, they went to 30 # on the 11" Dalgrens. Two things you should know , The navy hated John Ericsson with a passion and the only reason the ship was built, was because Abraham Lincoln intervened with the Navy ironclad committee ( 1861) . In 1843 . Ericsson designed/built a Steam Frigate, the Princeton . and a gun called the "Peacemaker" designed by Ericsson's partner ( who was very well connected politically ) blew up and killed the Secretary of the US Navy . The partner blamed Ericsson for the killing , even though Ericsson had warned him the gun was unsafe.
This "memory " by the Navy caused the reduction in powder levels IMHO. What is also interesting is the ship was owned by Ericsson (and investors) at the time of the battle, and the next day, the Navy bought the ship from him for $ 280,000 .

Another side note, Ericsson designed a wonderful recoil system which was used, and asked for 15 inch Dahlgrens , but was given 11" guns instead
But the most amazing fact that needs repeating ;
This First- All Iron -steam powered - rotating turret- ship.....was built in 100 days !--------980 Tons of metal
And no CAD or CNC
Rich

[SteveM]

This deserves some sort of award.

See here:
http://craftsmanshipmuseum.com/Carlstedt.htm

I got to meet Rich at cabin Fever maybe 5-6 years ago and see the engine running.

The pictures and videos do not do it justice.

Steve

[Greg_Lewis]

Oh my. A master craftsman and most deserving of all the recognition.