I just had lunch with my grandson, Michael-Bryan, who is in the US Navy. He serves aboard the USS Denver. Her mission is to transport and launch large USMC landing craft. He is in the deck department and among his duties, he actually gets to drive Denver. It was not so long ago that I would not have trusted him to drive my Chevy.
Denver is the second oldest commissioned ship in the Navy (Constitution is the oldest but never leaves Boston), having been launched in 1964. So, she is a Vietnam vet.
But here is the cool part from our prospective ...... Denver is one of three remaining US Navy ships that is ........... wait for it ............
....... steam powered. Two boilers, two steam turbines, two shafts, 24,000 shaft horsepower (18 MW) (whatever all that means).
My grandson is a steamboater (kind of).
My guess is that the USS DENVER's two steam turbines are hooked up to two electric generators rated at 18 megawatts. The created electricity is used to turn electric motors which power the propellers. The great French ocean liner NORMANDIE built in 1935 had this sort of system along with the two Charles Ward Engineering built monster towboats INDIANA and LOUISIANA. One of the advantages of turbo-electric power is that the boat has as much power to back as to come ahead.
In later days the Cunarder QUEEN ELIZABETH 2 had her steam machinery removed and replaced by a diesel electric system. Instead of steam turbines turning the electric generators, nine diesel engines, each nearly the size of a modern American railroad locomotive, created the electricity for the house load and her two propulsion motors. She could back faster than most modern ships can run ahead!
*Steam still in use by world navies*
Hi, Paul, Frank & Steamboating colleagues:
Thanks to Paul for his insights on the USS DENVER and Frank's technical data. In spite of increasing use of powerful diesel, gas turbine ship engines, steam still is considered more reliable with less down-time for maintenance and repairs. Diesel and gas turbines may be quicker in a 'reverse order' with steam taking longer to close, put in reverse. Our U.S. and British navies still employ steam turbines for aircraft carriers generated by conventional boilers or now nuclear reactors. French and Chinese navies use steam linked to, as Frank mentions, 'turbo-electric drives.'
Frank on the money RE: the great NORMANDIE lost all too soon in her career by a disastrous fire in New York at the Hudson River pier while undergoing conversion as a troop transport renamed the LAFAYETTE in World War II. But that's another longer story with vivid memories my late father had of the disaster in his navy career. French designers also reconfigured the three huge uptakes from the NORMANDIE boiler rooms to split in a 'Y' configuration to free up more open interior spaces unobstructed for those incredible expanses of open salons, stair cases, dining room. The 'Y' uptakes were port and starboard again merging for smoke exhaust in the top funnels. The sage CUNARD LINE continued to follow the design of funnel casings/uptakes in the center of their ships. I well recall crossing on the then new QE-2 during her first 16 months of operation under steam. Admission was granted to tour her boiler and turbine rooms with all fresh, clean, immaculately painted with the blue steam turbine casings. Three CUNARD engineers sat or strolled around a bright, clean control room looking through glass windows. Now and then then punched a button, turned a dial and wrote down in a log what they did all so casually. What steam the QE-2 vented from her one unusual stack appeared to me to be very high pressure in a blue/white color with a powerful hissss like a knife and not the wet roar of steam we often hear on steamboats. When CUNARD removed her conventional steam propulsion system they had more than a few pains with her diesel electric system causing unusual vibrations being most uncomfortable in her stern quarter. They returned the ship to be further modified with a system of shock absorber mountings to control the vibration. One single dent the size of a quarter on those huge ship props can cause vibrations too.
Frank could possibly tell us from his experience how these new mounted 'ship pod' drives that swivel can also cause problems--and many big 'blue water' ships have and continue to experience. My memories on the old QUEN MARY and QUEEN ELIZABETH were of their vast banks of oil-fired boilers producing an awesome amount of horse power. May not be 'pure steamboats,' as we've heard here before in strident tones, but it does link to Paul's initial posting. Well, what do I know?
R. Dale Flick
Coal Haven Landing, Ohio River, Cincinnati.