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Driver’s Education, US Navy Edition
There was very little mainstream media coverage but the United States Navy proved again this week that no matter the size of the ocean, they will take a ship and hit something with it. This time, it was another one of our ships.
On Tuesday the USS Leyte Gulf (CG-55), a guided-missle cruiser and the USNS Robert E. Peary (T-AKE-5), a supply ship, collided during a training exercise off the coast of Florida. No one was injured. The Peary came away with an 8-inch gash above its waterline. The two ships were practicing an “underway replenishment” in which supplies are passed from ship to ship via rigging traveling together at speed.
The Leyte Gulf is currently assigned to carrier group of the USS Abraham Lincoln (CVN-72).
Hat tip to the US Naval Institute News.
Published in Military
Actually you have that backwards. A few years ago the USNA decided to resume teaching celestial navigation. They stopped about a decade or so ago.
When I was in NROTC at Notre Dame, navigation was considered one of the toughest courses at the entire university. I’m not sure how true that was, but many people believed it.
That’s what I said. They stopped and then rethought it. And they started up again.
I am astonished that there are not more collisions during underway replenishment, or during aerial refueling, which is performed for both fixed and rotary wing aircraft across the services.
I’m curious as to how the collision happened between the two ships’ sterns. When alongside each other there is a venturi effect between the ships which tends to pull them together and requires the receiving ship to steer slightly away from the ordered course most of the time to keep the distance between the ships constant. I don’t think this would explain the sterns hitting in itself but might have been a contributing cause.
When UNREP is completed and all connections broken between the ships, the receiving ship increases speed and gradually steers a course more and more away from the base UNREP course that the replenishment ship maintains during the whole evolution. If the officer with the conn (verbal control over steering and engine orders to the helmsman and lee helmsman) on the receiving ship ordered too big a course change too early it would cause the stern of the receiving ship to swing in toward the replenishment ship and could explain the stern to stern hit. It is also possible the helmsman made a mistake in steering independent of the orders from the officer with the conn.
I served on an ammunition ship 52 years ago, considering how long the Navy has been doing ‘ unreps ‘ and how complicated an operation it is* , I’m surprised there hasn’t been more accidents of this type. I’m sure this is an accident and not caused by the negligence evident in the other collisions we’ve heard of recently. It is the job of service ships to operate in close quarters with other ships.
* Two (sometimes three) large ships tethered closely together maintaining the exact same course and speed for several hours.
The Peary is a dry stores (K) and ammunition (E) ship, not an “oiler”, so they weren’t transferring fuel. However, Unreps are performed in the same manner despite the commodity.
https://en.m.wikipedia.org/wiki/USNS_Robert_E._Peary_(T-AKE-5)
Here is a photo of similar ships from Wikipedia.
When I was on a destroyer on the “gun line” during the Vietnam war, we unrepped about every three days for food, ammunition, fuel (beans, bullets and black oil) and/or parts. Occasionally personnel transfers.
One of the strengths of the US Navy is that no other Navy in the world has mastered the unrep like we have.
Theoretically four. Aircraft carriers of the time ( I don’t know about now) were also equipped to refuel smaller ships. So you could have a destroyer taking fuel from a carrier which was also taking ammunition from an AE which was also giving ammo to another combatant on the other side. I never saw it done. But unrep on two sides was not unusual.
@rightfromthestart, which AE were you on?
I’ve conned a ship alongside during UNREP and I’ve also been a master helmsman executing the conn’s orders. It ain’t easy. A half degree course change or a couple of rpm speed change can make a big difference. In this case the ships were making a simultaneous turn, which is even trickier. I’m with those pointing out that the real surprise is that the Navy does does so many replenishments without collisions. I wouldn’t sweat this incident. While unfortunate, it is not in the same category as the 2017 collisions.
I’ve considered that , I don’t recall ever seeing it. I was on the USS Mauna Kea AE-22, every two years or so the guys from that era hold a reunion at various locations around the country. We were in San Diego last October.
I was on the Lynde McCormick in 1970 in WestPac. I don’t recall for sure but we probably rearmed from Maura Kea. She was there at that time.
http://www.navsource.org/archives/09/05/0522.htm
I do remember unrep with USS Sacramento, AOE1, a much newer ship.
Without the other incidents this probably wouldn’t have gotten anyone’s attention. The USNI reporting caused the Navy to issue a statement. They could have served themselves better if it had included the lines, “The Navy does X of these every year and 1 in Y leads to minor collisions such as these.”
Learning a lot here; thanks to all!
Waves and wind are real things as well.
Oh kayy. One cannot hold a stationary ship in any alignment. One cannot control the orientation of a ship unless it is under power.
Anchoring in the ocean.
One thing
I haven’t seen mentioned here yetI should emphasize [edit] is the venturi effect. When the medium (air or water) between two surfaces is flowing, the pressure between those surfaces is reduced. Since the pressure elsewhere is not affected, the two surfaces are pushed together. That makes connected refueling (the USN’s preferred means of UNREP) particularly challenging for ship drivers.We’ve only had around ten nuke powered cruisers. The cost just isn’t justified for small ships.
I believe USN protocol requires career destruction of some commanders and senior crew and an official finding that there are no broader training, design or competence issues.
Maybe a Squid confused the translation of leagues, fathoms, to feet.
Lots of great info here from some old salts. Just a few thoughts:
If you want to be a super power, you have to “command the seas.” That means your global navy never runs out of missiles, fuel, Coca-Cola, or condoms, and your warships don’t have to stop somewhere to get that stuff. Russia never could pull it off. China has a long way to go.
The USN can replenish from its own ships, from NATO ships, Japanese ships, and others, and they do it constantly. No doubt a USN ship is doing it right now.
Deployed ships need to be combat ready. This includes not letting fuel and stores drop below certain levels. The Admirals get uneasy when some ship’s fuel gauge drops below X%.
USS Leyte Gulf runs on four General Electric LM2500 engines, so essentially it’s powered like a 747 or a C-5. It burns tons and tons of fuel, especially if it needs/wants to go fast.
So, imagine this ship is in San Diego and gets orders to get underway and head for the South China Sea, 6,500 nautical miles away, at best speed. She departs San Diego. Instead of stopping at Pearl Harbor for fuel, a tanker goes out to meet her. A few days later another goes out from Japan. On arrival she tops off from a ship out of Singapore and is ready for action. Actually she probably has been ready for action during the entire transpacific journey.
In case you haven’t thought of it, this costs lots of money.
As for anchoring, the average depth of the oceans is 2.3 miles. That’s a lot of chain!
And the other part of the nuke cruiser economics is that they still need to replenish food and ammo. A nuke carrier also needs to do that, so they aren’t without needs. They also need to refuel jet fuel. What nuke power does is give them a lot more room for jet fuel.
Error here, none of this was written by me.
Sorry, I tried to quote part of your comment not the entire post and add my own comment, now in boldface. I should have used the quote function for you entire comment and then edited out the portion I was not responding to.
And yet none of it was mine! It gets tricky sometimes, especially on a phone or ipad, when it is impossible.
Thanks, @pilgrim and @skyler for ignoring logistical snags in order to continue the conversation! I appreciate it…
Looks like @jro ‘s comment was attributed to @skyler. Whatever, it was interesting
The thing about the last item you mentioned as being a new aide for navigation: “pseudolites”—ground-based devices that beam GPS-like signals and are already being used in the commercial sector, is that man and woman made devices can usually be hacked, whereas so far no one has hacked the actual stars in the sky.
We have a decoder ring.
I am trying to figure out how the net torque on either vessel is zero, which obviously it is in this configuration.
With the vessels oriented at an angle, it seems that the relative waterspeed on the inward-facing hull sides would increase as you go aft, meaning the pressure would be lowest at the sterns?
Is there a counter-balancing low pressure on the aft portion of outward-facing hull sides?