March 01, 2019

Pictures - Iowa Engine Room

As a follow-up to my previous post with picture of Iowa's boiler room, I've put together a set of images from the engine room. I'm not going to spend a lot of time reviewing the actual mechanics of the ship's propulsion system, as I've discussed them at length elsewhere.

You step off Broadway, and into a tiny atrium, then go down one of the longest and steepest ladders in the ship. It's tricky even for me, and I'm pretty sure-footed around ships.

The ladder down to Engine 2. The yellow-and-black striped box is for lubricating oil.1

The most obvious thing is the reduction gearing, which steps the fast-rotating turbines down to the speed needed for the propellers.

The top of the gearbox in Engine 22

The reduction gearbox. Note the crew signatures from the decommissioning crew.

The high (left) and low pressure turbines, with the crossover pipe connecting them

Behind the turbines is the throttle board that controls the amount of steam let into the turbines. Conditions in the engine room were harsh, with temperatures often exceeding 120°F. The machinist's mates who ran the turbines drank lots of water and often failed to wear shirts.

The throttle board. The red wheel lets steam into the reversing turbine, while the green wheel controls the ahead turbine. They should not be opened at the same time.

The throttle valve which controls how much steam is let into the turbine

To back up the instruments, the man at the throttle board had a mirror which let him see the shaft as it left the gearbox (a closer view, below).

The condenser is on the lower level of the engine room, incorporated into the low-pressure turbine casing. It turns exhaust steam into water by passing seawater through a series of tubes to cool it.

The seawater intake for the condenser. At high speed, the motion of the ship rams water in, but at low speeds, a pump, such as the "Bilge Dragon" in the center of the shot is needed.

The condenser, showing the green piping for the seawater

On the other side of the engine room from the turbines are some of the ship's auxiliaries, most notably two of the 1,250 kW Ship Service Turbogenerators (SSTGs).

The turbine end of one of the SSTGs

The generator end of an SSTG. Note the painting on the far end of the SSTG.

Degaussing coils, intended to protect the ship against magnetic mines

The main switchboards in Engine 2

The condenser for one of the SSTGs, down below the generator unit. The access doors are open, and a zinc anode to prevent galvanic corrosion is visible on it.

The engine rooms turn the steam generated in the boiler room into both motion and electrical power. It's one of the largest spaces in the ship, and incredibly cool to see. If you want to visit it, Iowa offers the Full Steam Ahead tour, and I'd encourage you to take it.

1 All pictures from my collection.

2 The locks on the hatches are to prevent the crew dropping things into the gearing, which can put in a ship in the yard for months.


  1. March 02, 2019CatCube said...

    These are some awesome pictures.

  2. March 03, 2019Neal said...

    Is that story of the destroyer William D. Porter almost torpedoing the Iowa really true? Last night on a pilot's forum I read a rather amusing (if one can view it that way in retrospect...) account of the Porter launching a torpedo at the Iowa on 14 November 1943 as President Roosevelt was being transported to meet Churchill. Disaster was narrowly avoided apparently.

    The account bordered on being fantastic and I thought I would check in here to see if it were true.

  3. March 03, 2019bean said...

    Yes, it is.

    (That said, most accounts you find include a lot of details that didn't actually happen.)

  4. February 19, 2021Blackshoe said...

    Two thoughts:

    1. Lulz at the Danger tags still hanging in place.
    2. Someone in EM-02 was a pretty good artist.
  5. February 19, 2021bean said...

    There's lots of tags still aboard. In the aft fire control room, there's tagouts on the circuits for Turret II. And yes, there's a lot of crew art, most of it quite good. Probably has to do with having a crew five times the size of a destroyer.

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