Hedgehogs and Depth Charges with

[@inventor226]

I visited the Slater with my grandfather about 10 years ago. It was a great tour, the tour guide even took us to a, as of then, un restored and off the tour route engine room as my grandfather served on a fletcher class destroyer in an engine room. It was great as my grandfather was able to compare the difference and similarities between the two ships. We also visited New Jersey around the same time. I am glad I was able to before he passed away.

[@jth877]

Almost everything does work on Slater. From steering, desiels, search lights, full galley, and much more. Awesome ship to go see.

[@LeCharles07]

"About 78 lbs" "So that's-easy for a single sailor to move em." "Your back problems are not service related."

[@oml81mm]

Not mentioned is the fact that the hedgehog is a spigot mortar which means that once reloaded (which is quick) it is ready for firing instantly

[@paulfarace9595]

Good point! But time is limited on our programs so we have to skim over a lot of great information!😢

[@USSSlater]

I'll add that SLATER also had a ready service locker just outside the main magazine (plus two more lockers for 3-inch rounds). These were removed at some point after the war or during her Greek service. One of the lockers was also tossed overboard after a storm ripped it off the mounting brackets. The hedgehogs inside were tossed overboard as were any other rounds that were dropped on the deck.

[@kevinalexander7710]

Ryan, I really appreciate what you’re doing with the Cod lately and bringing more views to them. The Cod was the first museum ship I ever visited and got me hooked.

[@bobbenson6825]

I didn't have much familiarity with hedgehogs so this visual overview is a treat. It's always nice to see Ryan cross-promoting with other ship museums.

[@grizwoldphantasia5005]

One of the advantages of Hedgehog was that they only exploded on contact, whereas depth charges always exploded, and they roiled the water so much that it took several minutes before sonar could get a clear picture again. (I am no expert; "several minutes" is what I remember, but take it with some latitude)

[@edfrawley4356]

The time it takes for air bubbles to reach the surface depends entirely on the depth they where formed. Bubbles rise at 18.8cm/s so a depth charge going off at 30 meters (98ft) would take 159 seconds or about 2.5 minutes to reach the surface and burst. So several minutes seems pretty reasonable

[@tomtrenter3208]

Regaining contact also depended on the relative positions of the sub and the attacking sub hunter. Another factor is how deep the water is and what type of bottom because the ocean is a huge echo chamber. Deep water with a smooth bottom and it can echo for some time. Shallow water and rough terrain bottom will reduce the amount of echoing.

[@garywayne6083]

I had no idea they wee trainable - mesmerizing to watch!

[@jasondavidarchibald]

No sub is friendly. God, you’re the best Ryan.

[@AndrewGraziani-k7d]

Well, thanks. That was the best explanation I've come across about the advantages of the Hedgehog

[@chriskeating-wh7yw]

The Hedgehog..another great British invention.

[@RickLowrance]

Very cool. It all looked so new that I was wondering if the fellow in the yellow shirt might be arming the projectile by spinning that little device so much. :)

[@paulfarace9595]

I was wondering if I shouldn't be doing that myself but it's all so cool ...😮😂❤

[@jeffreyyoung4104]

@@paulfarace9595 I imagine all the munitions are inert. As having civilians on the ship would be a chance to have an accident!

[@WarpedHorizon]

"Everything on the Slater still works"... Spins a fuse.

[@hermanhahn3382]

😅I love these collaboration videos! Great wealth of information, love the banter, and the back and forth discussions. I also love that you have two experts discussing a ship that is not their own. Really puts USS New Jersey and USS Cod and USS Slater in a larger context. Would love to see move from both curators with other curators of other ships in the museum fleet. Would also love to see the outtakes too.

[@steveturner3999]

A great feature of the Hedgehog is that if it missed it didn’t interfere with your sonar search. Regular depth charges exploded regardless and interfered with the sonar’s ability to search.

[@geoff1201]

Another brilliant British invention.

[@shaider1982]

Interestingly, USS Slater has one sistership that is still in active service with the Royal Thai Navy.

[@jimmiles33]

That ship capsized while awaiting scrapping. It’s ex USS Atherton.

[@wembozandco.807]

I am loving these crossover episodes

[@craigtupper103]

That and the type 271 radar virtually changed convoy defense tactics overnight for the RCN and RN.

[@dutchman7216]

Loved this episode.

[@jeffreyyoung4104]

Great video! When the blades on the warthogs were spun, I was worried it might arm or detonate, but I suspect all munitions are inert, but like a gun, always treat it as it was loaded and ready to go BANG!!

[@StephenRWilliams]

I'll be sure to visit Albany one day so I too can spin the diddly bits.

[@BrianSmith-ow9gy]

Interesting that USS England had so much success with an English (British) WWII development.

[@keithrosenberg5486]

The WWII DE is my favorite small USN warship.

[@Ogre-zr5zk]

Anyone else get a chill up their spine from the figgit spinning???

[@quartertwenty484]

Especially because cluster bombs arm that way.

[@krashd]

Although everything works there's no chance that there's anything explosive on board, it would be far too tempting a target for thieves and would require a mountain of paperwork to legally store.

[@stewarttrains98]

I was on the slater several months ago. Was a great experience

[@Joe-lb8qn]

My late FIL was in the British navy in WW2. He was on very dangerous routes like the russian convoys. I wish he could have lived long enough to see some of these documentaries.

[@henrycarlson7514]

So Wise , Thank You

[@kristoffermangila]

Now you know why the Aussies wanted to strap on an armored, 7-shot Hedgehog launcher at the back of a Matilda II infantry tank...

[@bigsarge2085]

👍👍

[@burroaks7]

very cool

[@TheEulerID]

I believe the USS England became legendary for sinking six Japanese submarines in twelve days using Hedgehogs. Apparently at one time, depth-charges had a kill-rate of about one in sixty attacks, whilst with the Hedgehog it was one in five. It was developed by part of the British Admiralty with the rather ad-hoc name of the "Department of Miscellaneous Weapons Development" (DMWD). It was one of those simple, but brilliant ideas that made a huge change. The DWDM came up with some weird ideas, some like the Panjandrum were disastrously bad, some like the Mulberry Harbours used in the Normandy offensive or the method of de-gaussing ships against magnetic mines were very successful.

[@Knight6831]

The Mark 15 Hedgehog anti-submarine mortar the spam weapons of anti-submarine warfare

[@tomtrenter3208]

The Mk- 15 mount wasn't used until after WW2.

[@danquigg8311]

Did the hedgehog also have some sort of sympathetic detonator, so that the entire barrage would detonate when any one exploded on contact?

[@keithrosenberg5486]

USS England used Hedgehog sinking all those Japanese subs in a couple of weeks.

[@oliverwells8011]

Im a 170 lb strong guy, 78lbs is manageable but definitely not easy, especially if you.have to do it quickly

[@Whatsinanameanyway13]

Sure, but if your life and the lives of the people around you depended on it, I'm sure you'd find the strength. I imagine there would be a group of sailors handing these between the ready service magazine and the launcher, bucket brigade style.

[@robertthomas5906]

I think you'd be fine once you're out of boot camp.

[@tomhenry897]

When 18 doesn’t bother you

[@jarroddraper5140]

After setting corner posts, that sounds like a heavy line post in a barb wire fence and that is luged some over ruffer paster not a nice moving deck. Any one know witch is worse all the ships in been on had smooth sailing

[@1320_ikimasho]

In what range would one of them need to be in range in order for it to detect the uboat? Also, what happened if it just didn't detect anything~ would it just sink to the bottom?

[@terryrogers6232]

should certainly say that like the Mustang's engine, this invention is British and is an example of the cooperation both ways during the war. To be a bit more clear, Sonar (ASDIC...also British) lost contact even before the ship went over the submarine position giving a relatively long time for the submarine to make a diving turn. That guaranteed the depth charges were set wrong unless the captain made a good guess or did a nice spread (but then the distance thing you know). The Hedgehog was designed as a partner to Sonar being fired while the operator still had a good fix. The circle pattern meant a turn as a turn into the bombs. Contact ignition meant there was no fooling the depth setting. Note that the other bombs were 'sympathetic'...they would all go off when the first one did from a contact strike. At least this is my understanding of how the system worked. Later in the war, British hunter groups would stay with the contacts and ring the submarine until they killed it. That is, you as a submarine commander surrendered or died.

[@Mark-lv1ub]

Ryan, or anyone: what is the battleship that appears in the movie, "Don't Look Up", at about 51:30-52:00?

[@givenfirstnamefamilyfirstn3935]

Was the launcher stabilised against ship roll?

[@rpddsmith]

Hard to believe that one hedgehog round has as much explosive filler as a 16" ap round

[@mcmneverreadsreplys7318]

I would like to see a comparison of the British Hedgehog to the American Mousetrap. I have been told the Hedgehog was mortar fired (which was hell on the decks) while the Mousetrap was rocket fired. You can see the difference in vintage film because the Mousetrap projectiles have a fire trail while the Hedgehog projectiles have only a smoke trail (if that).

[@voiceofraisin3778]

The frame underneath has sprung suspension to take up some of the recoil. the launching charge is black powder so has a lighter kick than faster burning modern propellants. Since the charges are ripple fired theres also limiting on the strain on the deck, if they all fired at once then you'd strain the planking. Hedgehog was also flexible in how it was fitted, larger ships with suitable decks got the full size launcher, if there wasnt enough space due to gun mounts or unsuitable deck structure it was also possible to fit a split hedgehog where instead of one large bank of launchers they fitted two smaller lauchers away from the centreline. The main problem with mousetrap is that its rocket fired, the launch frames are fixed and the gunner cant stand near it. Hedgehogs gunner stands directly behind the launcher and can adjust angle and range so can make adjustments for sea state as well as accurate launching. You cant see him in the video because of the angled steel plate behind the projectiles but hes the one using a hand wheel to bank the trunions. So hedgehog strains the deck more but it has far more benefits in accuracy. It should also be pointed out that Hedgehog was an interim weapon and had some design problems, it was quickly succeeded by Squid, which was directly linked to the sonar ranger and had far more accuracy.

[@tomtrenter3208]

​@@voiceofraisin3778 Squid was an interim weapon and so was the British Limbo and American Weapon Alpha. Acoustic torpedoes replaced all of them and remains in service today.

[@Joe-lb8qn]

@@voiceofraisin3778I love these names.

[@pelmen1294]

:) Dont forget the squid launcher .

[@StrikeFreedom21A]

Evening all

[@argusmac9056]

You completely forgot to mention that these were a British invention.

[@missyd0g2]

Great team of historians

[@thomasg4324]

*70lbs?......I'd rather have twice as many 35lbs hedgehogs spread over a larger area.* I'm surprised no one thought to have drag lines to snag a U-boat, and draw the explosive up against the rear hull.

[@tomtrenter3208]

I don't know where you got your info from but hedgehogs weigh 65 lbs ea.

[@alexmelia8873]

IDK. That guy runs a museum ship and is literally standing in front of a rack of them. You've got a tall order to overcome his expertise.

[@tomtrenter3208]

@@alexmelia8873 I was a sonar tech and we were trained how to use them.

[@tomhenry897]

Said about 78

[@paulfarace9595]

There were various types of hedgehogs... with slight weight variations between them ... and we were reading the weight stenciled on the weapons!😂

[@tomtrenter3208]

@@paulfarace9595 I don't think there was a weight difference that large for such a small weapon. It would seriously affect it's ballistics and if you increased it's propellent the recoil would cause even more serious damage to the ship. Hedgehogs recoil had a bad habit of breaking light bulbs and any other kind of glass in the forward part of the ship, betcha history books don't tell ya that. Any of ya ever heard of a weapon we had called "mousetrap"?

[@merlinwizard1000]

41st, 28 September 2023

[@StrikeFreedom21A]

@knight6831 hedgehogs are awesome

[@jkilby27able]

👍👍👍