Otto Gross and the L-8 Ghost Blimp

I was doing my podcast on the mystery of the L-8 Ghost Bimp of 1942. During my research, I discovered the name of Otto Gross who had done extensive research in the subject. I wrote Otto and he was nice enough to write back. This is his letter.

Hi Jeff,
The L-8 story ends with the crash in Daly City,Ca. and the disappearance of the two crew members. The trail I’ve pieced together that leads to starts in New Jersey.

As the Axis threat grew the United States started developing technology that would be used in what many considered an inevitable war. A government agency called the NDRC, National Defence Research Committee, was formed from private industry, government and military bodies, and universities.

All the important technology developed for the war came through this group. The NDRC would be reorganised in 1942 under the name, OSRD, Office of Scientific Research Development. The change was necessary for reporting purposes. In the NDRC military personal sometimes reported to university professors. In the OSRD the military took a more joint lead and civilians were given a honorary military rank for purposes of reporting hierarchy and travel, for example. The NDRC model had a general reporting to the 19 year old head of the radar division.

Clearly an odd, unmanageable arrangement when someone commanding thousands of men has to work around things because it’s a school night. And radar becomes and important bit in the L-8 story.

The story of radar starts with the Tizzard Mission – British diplomatic group that came to the US to get Lend-Lease going. The British had made a major improvement in radar by developing the 3 centimetre magnetron. Older 10 cm magnetron were unable to “paint” finer detail. If you think of radar like painting a portrait, a 3 cm magnetron would be like having a 0001 fine brush while the 10 cm is something you’d find in the house paint aisle. Given that the original radar scopes came in two sizes – 2.5 inches and 3 inches, radar in then early forms were not very useful. And radar was heavy – too heavy and big to put in a plane. The average up time for radar units was measured in minutes as vacuum tubes and magnetrons failed regularly.

Radar development was farmed out to a number of companies given that it was as big a secret as the atomic bomb. Philco was the primary contractor,who along with Westinghouse made most of the components. Western Electric and Bell Labs made the British magnetron into something more reliable and the size of radar units a fraction of the size and power they had been. A lot of the research and development happened in New Jersey. Bell Labs in Whippany NJ was responsible for the 3 cm magnetron. Westinghouse in Newark and Harrison made some of the components that would go to Philco in Phillie and Pittsburgh for final assembly.

Research- that’s where the L-8 story starts – happened at the Naval Air Station at Lakehurst and surrounding area. While famous for the Hindenburg disaster, Lakehurst was home to one of the most active blimp squadrons. Blimps were used to patrol the ocean for enemy activity. And most important to our story, they could hold a number of people and support large weight for extended periods of time making them perfect flying laboratories.

Radar was developed into many things – detecting enemy planes and ships was one of many. It was also used as a signalling mechanism we call IFF, Identification Friend or Foe – a Morse code like usage of the microwave signals generated from magnetron. LORAN, still in use today, was developed and tested at Lakehurst. Blimps with blacked out windows were used to fly along the coast, out to the tip of Long Island and as far as the Bahamas. Sidebar: Division 14 of the OSRD was for radar developement, Division 15 developed anti-radar devices; jamming etc. Donald Trump’s uncle, Dr. John Trump was a scientist in charge of projects for Division 15 as well as holding what we now call the Chief of Staff position for the 14 and 15 divisions. No matter how one views his nephew

Lakehurst had the secret Radar School.

The turning point in the story from the East Coast to the West Coast occurs on the evening of June 8th, 1942. Lakehurst was also the test site for many other projects. The one being tested that night was a photoflash bomb that was developed in the hope it could light up a submarine from underneath. Subs were hard to detect. Something called MAD, Magnetic Anomaly Detector, a flaying version of a metal detector was used with no real success. The blimp had see a periscope or conning tower, fly towards the descending enemy sub at a blinding 7 mph, then circle the sub sitting at the bottom where it thought it might be but not see. In controlled tests MAD had less than a 4% success rate.

That would be a clue into the story later.

The L-2 and G-1 blimps went out that night with 13 crew members, planning on using a Coast Guard cutter as a standing in for the outline of the enemy sub. The plan was to have the G-1 circle the CG ship dropping the underwater flash bombs while the L-2 filmed the flash and ship outline to see what formulas and colors worked best.

While they circled above the cutter, the L-2 crashed into the G-1. Both blips deflated and fell into the water. Only one man, the pilot of the L-2, survived by jumping through the window into the water. The balloon envelopes covered both gondolas as helium leaked into any air pockets. Those that didn’t drown in then water died from anoxia as the helium displaced the air.

The gondola of the G-1 detached as the crew of the cutter tried to uncover the wreck and free any trapped men. It appears from my research that it still sits on the ocean floor – or what’s left. The L-2 gondola was dragged onto Point Pleasant Beach – near where the show about New Yorkers acting badly,The Jersey Shore, was filmed.The L-2 was cut up on the beach and everything cleaned up within a couple of hours. Bodies would be found for months to come. Only one man, Dr Franklin Gilbert. Originally from Newark, Dr Gilbert eventually would be head electrician for Paramount Pictures developing sound before volunteering to transfer to war work in Groton CT involving acoustics. NDRC/OSRD civilians were paid the rate their normal job paid. He never had a memorial service and they never paid the same insurance policy Congress granted other civilians killed in action.

The next morning the papers had the story of the crash on the front page, letting every spy in the area that “work of secret nature” was being done at Lakehurst.
Salt Water Taffy, The Boardwalk, and State Secrets! Hazzah!

Well the government moved everything including teh radar school to California. Moffet Field and Treasure Island, San Francisco.

Your listeners may or may not have heard of Treasure Island. It was part of the Moffet Field NAS and the main building at the entrance was used in “Indiana Jones and the Last Crusade” for the airport scene involving the blimp flight.

The L-8 was shipped to Treasure Island, Moffett as a replacement for the L-2.

For those unfamiliar with the L-8 it took off on August 16th from Treasure Island. originally three men would have been aboard but as it floated down the runway to takeoff, the mechanic was told the blimp was heavier than usual and he would have to stay. Cody and Adams took off for the sub chasing flight patrol from San Francisco to the islands off the cost, up to Point Reyes and back to base.The blimp was armed with two 250 pound bombs, a machine gun, and contained a raft. It contained secret orders. The pilots wore standard May West vests.

About an hour into their flight they spotted an oil slick on the water, a sign a potential target lay underneath. They radioed back that they were investigating. It would be the last time anyone heard from them. A few hours later the deflated blimp glided into the beach across the Pacific Highway onto a golf course. Two men on the beach saw the L-8 come in and attempted to grab hold of the guide ropes but failed. They were observed by a librarian driving by. This would let to some confusion about the pilots later.

One of the bombs detached as the air bag acted as a sail, dragging the gondola. The authorities wee called and the Navy and Army sped to the golf course. Unfortunately, when the blimp – minus 250 pounds – became lighter and and the wind picked up, the L-8 lifted into the air again.
In the mean time a call was received back at Treasure Island saying the pilots were at the golf course. A short while later a second call reported tha tthe pilots were not there in fact and the blimp had gone airborn and heading towards the hills around Daly City.

A short while later the L-8 was spotted drifted towards Belvedere Ave in Daly City, it’s final resting place.

Firemen on then scene cut the envelope and ballonettes so it would not take off again. The door hung open with the gondola on end and they found no sign of anyone. and the first military people were on site.

And the Ghost Blimp Mystery was born as well as lots of the confusion.

Much that had been written was hearsay. Many speculation flew back and forth about Japanese subs, the possibility the sub flew too low and the crew washed away, murder/suicide plots, spies and lots more. There was little in the way of facts though.

The JAG inquest started a few days later and the witnesses called. I know this because it took me years to find the folder at the National Archives in Washington, DC. The file had gone missing at some point and it took many trips to discover it again. I kept getting pointed between the NARA site in DC and the one in College Park,MD and neither could find it. I ended up eventually talking to two older gentlemen about what I was looking for and one said “Remember that box Charlie had he didn’t know where it went?, too the other guy. Wait a minute”.
It was the box I’d been looking for. It contained then JAG folder but also had then blueprints for the original L-blimp, the L-1 – the Enterprise.

The inquest pointed out hat there were witnesses to the L-8’s decent. Two merchant ships heading into the Bay noted that it dropped a marker flare and circled the spot. It never got near to the surface before heading off.A sailor who was at a park near the Golden Gate took a fully inflated L-8 heading back to Treasure Island.

The significance concerns the poor hit success rate of the MAD device.

I came across some technical papers and letters describing that the T-R tube for early radar units leaked ( Microwaves).

The dish mounts were made of a polystyrene material that broke when the blimps bounced. This would make the dish not point correctly.

A letter from two NDRC scientists mentioned a device being worked on that would combine radar and MAD. If you know what side scan sonar; like that but for submarine target.
Radar research showed that using radar pointed at the sea with a near surface object would give results.

So the plan was to use radar to detect conning towers/periscopes and use the MAD/Radar combo to detect the large hull of the enemy below the surface. Most of the technical papers are located in the Boston NARA site and anyone who is looking for undiscovered treasure and surprises is bound to enjoy visiting and researching there. Technical papers are also found in the Library of Congress Adams building. .

Another clue was from a log book of a blimp out of Massachusetts looking for the wreckage and any survivors for a torpedoed ship from Europe. The Lt. wrote that the pace was artificial slow and he wished that he could tell people he had radar instead of making the normal serpentine path using search light to where he thought the wreckage would be. That confirmed the timing of radar use matched.

SO what happened Mostly I know the blimp deflated when it rose to high. There is an automatic valve that opens should the blimp go to high expanding the ballonets to near breaking point.

Why did it rise. Because it lost the weight of one of more men. This was confirmed by the sailors testimony who reported the ship pitched up and went into the cloud cover while heading towards the Golden Gate. It had been under level controlled flight before that.

The Pan Am Clipper, alerted to the missing blimp that failed to do an hourly report saw the L-8 under normal control and that they did not notice waving or distress. Oddly, the pass quickly and can’t confirm they saw pilots.

So my thought is that that something caused the L-8 to be one person to heavy. The weather report for that month showed almost no rain and the fog from one day is no heavier than the day before.

The behaviour of the L-8 trying to detect the oil slick is what was expected to do when using radar to detect underwater objects.

The blimp did not have pilots visible during part of the flight back.

Radar units had lots of problems that made them dangerous for people. A letter from the an Ohio air field commander said that his bombardiers and radio men were getting fevers from the radar. The letter back suggested wrapping his men in tin-foil. But it turned out he was right and microwaves are still causing something called AM radio fever. People near AM radio towers and microwave towers can get fevers of up to 106 and pass out.

Another base commander sent a note to his pilots threatening them to not turn of their radar units. It turns out that earlier units interfered with radio transmission and pilots were switching between radar on and off so they could communicate.

To me this sounded just like the circumstances surrounding what was described in the JAG report.

I believe the possibility that the men were disabled by radar units and they fell out while unconscious as they attempted to head back to base when radar leaked – preventing the radio from working and eventually heating them into insensibility.

In the military folder of the pilot of the L-8 I found a letter from his mother-in-law saying she was in Phoenix visiting and say we dazed and confused son-in-law. Both Cody and Adams were declared dead on the one year anniversary. People have survived falls from great heights but if you’re even seen the Myth Busters episode on whether that was true or not, survivors had similar symptoms caused by the effect of the impact on their brains.

I found the L-2/G-1 JAG folder – also misplaced in the folder of the commander of the G-1, Frank Trotter, and in the wrong year.

That helped solve what occurred with the L-2/G-2, and while not connected via radar showed how much we owe the men and women, civilians and enlisted alike and the technology that won the war and changed the world. It’s been a fascinating journey. I’m working on another,earlier part of the story related to spy activity in America that may or may not be part of the whole story.

After the war the L-8 eventually became the Good Year Blimp America from 1969 to 1984. After that it sat in a field rusting but was recovered and restored. The gondola now sits in the Pensicola NAS, a really great place to visit with a good research library.

Have a great Memorial Day and remember the crews of the L-8, L-2 and G-1!

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