Up Ship - Naval Lighter Than Air

[PhrogPhlyer]

I believe the blimp versus submarine score card is not particularly encouraging

The mission was not to find/attack a sub, it was to deter the sub because it could be seen by a blimp that could direct surface combatants towards the sub.

In WWII there was only a single occurrence of a ship being attacked and sunk by a sub that had blimp escorts.
When you look at the ships that were NOT attacked/sunk, the blimp significantly proved its worth in that mission.

These articles chronicles the exchange between the K-74 and U-134.

https://www.usni.org/magazines/proceedings/1979/august/incident-florida-straits

https://www.history.navy.mil/content/dam/nhhc/research/histories/naval-aviation/Naval%20Aviation%20News/1990/1997/march-april/blimp.pdf

Note: A common misconception is that K-74's Mark XVII depth charges failed to release as the blimp passed over U-134, however this is known to be false as the sub received below-the-waterline damage consistent with a depth bomb. This was stated in a Secretary of the Navy Letter of Commendation, 13 Oct. 1960

 

[Gatordev]

The K Class carried an ASG radar developed for large patrol aircraft and Navy blimps. It had a gyro-stabilized mount, and could detect large ships at 15 miles and a submarine periscope at 5 miles.

Yeah, 5 miles still isn't that far, but if the subs know it's out there, that's definitely a deterrent. My understanding is that the U-boats did have limited ESM, but I may be mistaken. Either way, that 5 miles would limit lines of approach pretty significantly, which would be a win.

They also carried MAD gear and sonobouys.

Okay, you made me google that one and learning occurred. I didn't realize buoys had been around that long.

As an aside I still scratch my head on how non-directional buoys are effective. I remember seeing the LOFAR patterns in the TACAID and I might as well have been staring at something written in Greek. But apparently they worked well enough.

The MAD gear apparently wasn’t that great

Every so often we'll have a Goodyear blimp overnight where I work so we get to watch the approach and landing. To my untrained eye, it seems like a blimp has to constantly make heading changes in order to maintain a course. I would imagine that didn't help with the MAD, as it was still a limitation in the 21st century w/out digital processing.

 

[PhrogPhlyer]

To my untrained eye, it seems like a blimp has to constantly make heading changes in order to maintain a course.

What you are observing is due to the constant variations of wind due to ground obstruction interference.
In an open environment, a blimp is very stable with a LOT of mass that needs to be deflected.

As an aside I still scratch my head on how non-directional buoys are effective. I remember seeing the LOFAR patterns in the TACAID and I might as well have been staring at something written in Greek. But apparently they worked well enough.

Mostly used in geometric patterns (X). Based on the returns you can determine position based on which buoys are giving return signals (and possibly strength of returns).

Similar to flying using NDB (non-directional beacons). Relative positioning to various beacons and your get your position.

On March 7 1942 blimp K-5 tested a hydrophone buoy on submarine S-20. It was found that detection was possible up to 3 NM. However, as the hydrophone was still non-directional several buoys were needed to localize a target. For this reason MAD was to remain considered the primary means of detection. The first operational sonobuoy was the AN/CRT-1 first ordered in June 1942. Operational use began in August of that year. This sonobuoy had 6 available radio frequencies and the hydrophone was omni directional. The buoy was capable of 6 hours of operation.

There is an excellent explanation of the pattern used for sonobuoys in the attached paper 'THE EVOLUTION OF THE SONOBUOY.'

Also, this article offers a nice overview of the WWII blimp and its ASW role.

K-Ships vs. U-Boats

Historian Thomas Paone explores the important role played by K-ships in hunting German U-Boats during World War II.

airandspace.si.edu

 

[wink]

As an aside I still scratch my head on how non-directional buoys are effective. I remember seeing the LOFAR patterns in the TACAID and I might as well have been staring at something written in Greek. But apparently they worked well enough.

Used a lot of LOFAR buoys on my first deployment in 1980.It wasn't unusual for the majority of the Hoover buoy load to be LOFAR. Also used non directional pingers (CASS), often dropped on a LOFAR in contact. LOFAR was cheaper and didn't use as many receivers or processing as DIFAR.

 

[Randy Daytona]

What you are observing is due to the constant variations of wind due to ground obstruction interference.
In an open environment, a blimp is very stable with a LOT of mass that needs to be deflected.


Mostly used in geometric patterns (X). Based on the returns you can determine position based on which buoys are giving return signals (and possibly strength of returns).

Similar to flying using NDB (non-directional beacons). Relative positioning to various beacons and your get your position.

On March 7 1942 blimp K-5 tested a hydrophone buoy on submarine S-20. It was found that detection was possible up to 3 NM. However, as the hydrophone was still non-directional several buoys were needed to localize a target. For this reason MAD was to remain considered the primary means of detection. The first operational sonobuoy was the AN/CRT-1 first ordered in June 1942. Operational use began in August of that year. This sonobuoy had 6 available radio frequencies and the hydrophone was omni directional. The buoy was capable of 6 hours of operation.

There is an excellent explanation of the pattern used for sonobuoys in the attached paper 'THE EVOLUTION OF THE SONOBUOY.'

Also, this article offers a nice overview of the WWII blimp and its ASW role.

K-Ships vs. U-Boats

Historian Thomas Paone explores the important role played by K-ships in hunting German U-Boats during World War II.

airandspace.si.edu

Just wanted to say thank you for starting this thread.

 

[Gatordev]

Mostly used in geometric patterns (X). Based on the returns you can determine position based on which buoys are giving return signals (and possibly strength of returns).

Used a lot of LOFAR buoys on my first deployment in 1980.It wasn't unusual for the majority of the Hoover buoy load to be LOFAR. Also used non directional pingers (CASS), often dropped on a LOFAR in contact.

I get the concept, but I've just had a hard time wrapping my brain around how you can get a fix with any kind of target resolution for a SAT drop. Not important for blimps, but certainly a thing for S-3s, P-3s, and H-2s. If I had to guess, one thing that made using the LOFAR easier back then was the significantly larger MDRs compared to today in many environments.

Anywho, success using LOFARs was obviously a thing and something I was impressed with...even if I never wanted to use them since I was spoiled with DIFARs.

 

[PhrogPhlyer]

Just wanted to say thank you for starting this thread.

@Randy Daytona, your ships thread got me motivated to start this one. LTA has always fascinated me, starting with watching Navy blimps cruising along the NJ beaches as a child. The going to airshows at Lakehurst with its impressive hangars, and having a retired blimp driver CMDR Charles A Mills as a German teacher in HS. As I learned to fly in college, and then into the Corps, my interest in LTA grew more.

LTA offers such a breath and scope of topics to explore such as, aerodynamics, aircraft design and materials, navigation, meteorology, SAR, ASW, weapons, ship patrol routes, hangars design and construction, communications, WWI, WWII, Cold War, DEW line, internal Naval politics, international relations and trade, helium trade and embargo, history preservation, and so much more, often shrouded in mystery and intrigue.

Once one get inoculated with the helium/hydrogen bug it never goes away.

 

[PhrogPhlyer]

Meals that are lighter than air.

Breakfast on the Graf Zeppelin airship.


Breakfast on a K-ship blimp.