The hotel load of a ship is the electrical power necessary for the operation of the ship other than the main motors.
It is provided by either shore power which comes from the wires connected to utility power ashore. When a ship is not connected to shore power then the power has to come from generators on the ship. Those generators are the hotel load generators.
The other aspect though was fixing their positions. That was managed against the British ships, obviously, but didn’t go smoothly, some of the Japanese bombers almost had to turn back before finding them. So this is another variable in ‘advance notice’. If the US BB’s had gotten enough notice to sail with full power available many hours prior to the attack on an unknown (to the Japanese) course it would have been a serious matter to find them and launch a coordinated strike, even assuming no US land or carrier based air cover for them. If they’d been rushing out of the harbor on a couple of boilers each when the strike arrived, it might indeed have ended up worse for the USN with more being total losses because sunk in deep water. It really depends what you assume.
To digress a bit, same goes to some extent for a/c getting off the ground, depends what exactly you assume. That would almost surely have resulted in fewer US a/c destroyed, but could have resulted in more aircrew losses, again depending how much time to form effective resistance, or for non-fighters to move away from the Oahu fields to where the Japanese fighters wouldn’t find them. Also keeping in mind the general (if minor) success of the US Army fighters in the actual raid benefited from the escorting Japanese fighters having seen no organized aerial resistance and gone to strafing. P-40’s downed several attack a/c (number will probably never be known exactly) with Zeroes busy strafing; P-36’s shot down 2 Zeroes for 1 loss in a dogfight late in the raid, Zeroes initially surprised; one Zero downed two P-40’s which had just taken off with the only air combat KIA of a US Army fighter pilot in the raid.
In the initial attack on the US fields on Luzon many a/c were caught on the ground but more US fighters rose to engage the Japanese ones than at PH, mainly from fields not under attack. 4 P-40’s were downed with two pilots killed, 2 others were write offs from air combat damage, all 18 P-35’s engaged were hit though only one seems to have been an immediate write off and none were shot down outright. Three or 4 of the 7 Zeroes which failed to return were apparently victims of P-35/P-40’s, the others to AA while strafing, all 7 pilots killed. That wasn’t bad for by the standards of USAAF (or RAF or Dutch) fighters v IJN fighters in air combat early in the war, but the US fighters were fully occupied by the Zeroes and the Japanese bombers were untouched by them. It gives one idea of a possible alternative scenario at PH.
Picture yourself riding a bicycle. Imagine you’re an airplane. Think of the ship you’re trying to hit as a soda can lying on the ground. You’re holding a baseball which is the bomb.
The first time, you’re going to try drop bombing. Hold your arm out to your side and ride the bicycle past where the can is. At what you think is the right moment, open your hand and release the baseball. You want to time it so the baseball falls down and hits precisely where the can is. Keep in mind that the bicycle, you, and the baseball are all moving so you have to drop the ball before it’s over the can. That’s hitting a stationary target with a dropped bomb.
Now imagine there’s somebody off to the side of the path and they roll the can across the path. You have to steer the bicycle down the path with your arm out like last time and drop the baseball at the right moment. But this time the can is moving. You have to steer the bicycle towards the can and take the movement of both yourself and the can into account to determine when you drop the baseball. And the guy who’s rolling the can wants you to miss. You can probably see why hitting this moving target is a lot more difficult.
Now imagine you’re a torpedo bomber. You’re still moving on the bicycle but this time you don’t have to drop the baseball precisely where the can is. Now you’re allowed to pitch the baseball like a bowling ball so it rolls some distance along the ground. And it still counts as a successful hit if the baseball strikes the can at any point. This shows why it was a lot easier to hit a ship with a torpedo than with a dropped bomb.
But a battleship’s length is 887 feet, and its top speed is 15 knots (figures I Googled for the USS Missouri). That means that it takes 35 seconds to travel its length. I’m not sure exactly how high planes would typically fly for an attack run, but 35 seconds is long enough for a bomb to freefall six kilometers, and I doubt that the planes were anywhere near that high up. In other words, in the time it takes a bomb to fall, the ship will travel only a small fraction of its length. Which means that, even if you aimed as though the ship were stationary, but it was actually traveling at top speed, any bomb that would have hit the stationary ship would probably still hit the moving ship.
Alternative histories are problamatic in that they assume a competence, experience and knowledge which just were not that at the time.
In hindsight, we all know how devastating the attack was going to be. In 1941, the USN (nor the RN) had not have developed doctrine for carrier warfare. Carriers were still be considered as an auxiliary to BB for scouting. The Japanese had actually pioneered the concept of concentrating the carrier forces to bring a massive number of aircraft to overwhelm the enemy.
At most, the US thought that at most, one or two Japanese carriers would attack PH, and most of the US commanders just didn’t believe it was possible for them Japanese to pull off.
The US still had a peacetime military. Poor communications, especially inter service ones, but also up and down the chain of command and within organizations. Operations weren’t smooth. Lots of mistakes were being made.
We assume that getting tipped off would mean that there would be a better response, but as can be seen by the clusterfuck in the Philippines after the attack on PH, the military just wasn’t ready.
What kind of advanced notice would have worked? Would they have been able to actually mount an effective defense?
It would have been easiest to man all the AA stations, with more ammunition ready ant NOT in locked storage. Water tight doors and hatches would have been set to Condition Zed, the highest degree of readiness. Some of the confusion could have been eliminated.
Excellent analogies. If I can, I’ll add that instead of trying to hit a rolling can, you are tying to hit an RC car who can change directions after you have released your projectile. For 45-knot torpedoes launched from 1,000 yards, it takes 40 seconds to reach the target in which a ship traveling 30 knots will move 1,000 feet. The BB at Pearl Harbor were slower so it would have been less time. Still this leaves time to maneuver, although large ships can’t turn on a dime.
In this case, the best way to hit the RC car is to have some friends come along, riding in parallel to you and you all drop your bowling balls together. It’s going to make it more difficult for the RC car to evade. And just for fun, have more friends come at the RC car head on (in the classic “anvil” attack) and also drop together. This was how the *Prince of Wales *was hit. The Repulse managed to outmaneuver 20 torpedoes before being caught in an anvil attack and sunk.
The other BB were faster, USS Nevada’s top speed was 20.5 knots, and it’s length was 536 ft.
The ships are going to be taking evasive actions even before the bombers release their bombs. Level bombers just were not successful in WWII.
Not to belabor the point, but there’s a mountain of practical evidence that WWII level bombers from even 10,000 or so feet had a very low hit rate in general against moving ships.
It’s worth noting that the closest to an exception to this was the Japanese Navy. Their level bombing did hit maneuvering warships in a number of cases. Part of the attack v Prince of Wales and Repulse on Dec 10 1941 for example was level bombing and there were hits though not important to the outcome, torpedoes were key. Later on in the Dutch East Indies campaign two US cruisers (Houston and Marblehead) were hit in one attack, the ex-aircaft carrier seaplane tender Langley was sunk by level bombers in the campaign, a Dutch destroyer was, etc. However they also missed or didn’t get enough hits to matter in a large % of all cases.
The problem wasn’t range error but azimuth. The bombers would as a rule attack along or close to along the long axis of the ship, attacking athwart didn’t make sense. The bombs would in fact generally land within the length of the ship. But to one side or the other. Not only from inherent error as against a stationary target, but because the ship could usually see the bombs leave the plane, then a skilled captain give a helm order after bomb release. Some of the few cases where the bombs hit the ships were where their bombs were not spotted. For example the USAAF actually hit a moving battleship with high altitude level bombing, not a Japanese one but the Italian Littorio in June 1942. The B-24’s attacked out of the sun, nobody on Littorio spotted the bomb release. But, a battleship attacked by relatively light general purpose bombs also wasn’t in much danger from a few hits: one 500# hit did minor damage to Littorio, near misses destroyed one of the floatplanes on deck. If Japanese a/c tried to attack moving ships with the large Type 99 armor piercing bombs used at PH it would be a lot fewer bombs than dropping patterns of 250kg or sometimes including 60kg ones as they did against moving ships. Those big AP bombs were intended basically against stationary BB’s, basically for the PH operation.
We were always on shore power. Sync up and shut down our 8 generators. The one exception was off-shore Pataya beach where we had to keep the plant running. Never heard the hotel expression before.
15 knots is too low. Even the Arizona could do 21 knots and the Missouri was faster yet. It could keep up with the carriers and was in fact specifically designed to keep up with the carriers. So at least 30 knots and I swear when the Jersey was with us, I was told she was a little faster then the Ranger and could do 33 knots and maybe a short burst to 35.
Somehow your googling went wrong on the speed. Please look into the battle of Midway for how tough it was for planes to take down the big ships. Plenty of later battles too.
But that’s assuming you can somehow just appear at the point where you drop the bomb. A plane obviously can’t do that. You have to fly your plane to the point where you can drop the bomb so it hits the ship. A moving ship will see this and will attempt to maneuver around so it won’t be at the target point that you were flying towards.
Here is Wiki on Missouri. Top speed, 32.7 kt Even Maine, laid down in 1888 and the one that sank in Havana harbor, could manage 16.4 kt.
I would channel Billy Mitchell and ask him about that fact.
TokyoBayer really knows his stuff on WW2. Altho we have disagreed in a few hypotheticals, his background info has pretty much always been spot on.
Ah, I see, I just misread the cite, since Google helpfully bolded the wrong part for me. It does in fact say 35 knots top speed. The 15 knot figure was economical cruise speed.
Wasn’t this one of the biggest disputes between the RAF and the RN when the former ran the Fleet Air Arm? The RAF was fairly certain that hitting a ship at sea was a non-starter unless you through scores of a/c at them.
Yeah, I guess he’ll have to ignore the fact that _Ostfriesland was statiinary and not shooting back.
Mitchell sank a ship with aircraft in 1921.
Wasn’t Yamato sunk by aircraft in 1945?
Glad you brought that up. This happened nearly 4 years later with advancements in radar, torpedoes, bomb sites and general pilot skill.
The Yamato went down but fought off the first 2 waves of planes. What made Ten-Go such a disaster for the Japanese was the lack of air support.
There are no stupid questions.
The answer is so incredibly obvious. . . but only since 1943 or so after repeated failures showed that the prewar planning was completely wrong. Prewar planning believed that level bombers (in which bombers drop bombs at high altitudes and in contrast to dive bombers) would be adequate.
In fact, the B-17 was designed to include coastal defense as part of its duties. However, level bombing failed to actually produce the desired results.
At Midway the USAAC got zero hits despite dropping using the famous Norden bombsight to drop 291 bombs from 4,000 to 25,000 ft, and the AAC only got one hit from level bombing in the Pacific up to Midway, and that was a ship at anchor.
The specially trained Japanese level bomber aircrews at PH managed to get an outstanding 20% hit ratio on the BB, although that percentage was boosted because bombs intended for one ship hit another. They simply could not have been able to repeat this against moving targets
Even stationary targets that small were different to hit. A two degree in pitch, for example caused the bomb to miss by several hundred feet.
Concerning the speed of the ships, the speed of the BB was of critical importance, but especially after aircraft carriers were introduced. Aircraft carriers needed to be able to travel at about 30 plus knots in order to launch aircraft.
Fast BB could keep up, but none of the old USN BB at the beginning of the war were fast. This had already limited their usefulness. The carriers were out on missions on December 7th and they had not taken any BB along because they couldn’t keep up if there was a need to cut and run.
It has been said the the Japanese actually did the US a favor by sinking and knocking out these WWI relics. Also, the peacetime navy was understaffed, with the intention of filling the ranks in the event of a war. Sinking the ships released these experienced sailors for duty on other ships.
The loss of so many of these giants forced the USN to quickly rethink strategies and doctrine to a greater degree than may have happened without the lopsided defeat. Ironically the IJN didn’t, despite or perhaps because of the win.
Thanks. I would qualify that to the Pacific War though.
We have our (strong) disagreements about hypotheticals, but that’s all good. It helps one clarify thinking.
The question concerning hitting the BB at Pearl Harbor was about level bombing (see my immediately previous post) and not dive bombing. The bombs dropped on the Yamamoto were from US dive bombers. Diving bombing had much greater in accuracy (possibly an order of magnitude, I’d have to look it up) as the planes essentially guided the bombs for the initial phase.
The US had AP (armor piercing) dive bombs and the Japanese did not. General ordnance bombs could other ships’ decks, including carriers, light cruisers, destroyers, etc., but couldn’t penetrate the armor on the BB.
Not just that: A plane can dive faster than a bomb can free-fall, so when a dive bomber released its bombs, they’d be going faster than a level-dropped bomb would be at the same altitude. A faster bomb means less time before it hits, which means less distance for the target to move.