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Rocket "Distress Signals"


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#1 Paul Lee

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Posted 20 February 2008 - 01:39 PM

Hi everyone,
This is my first post, so please be kind :)
A friend recently sent me a patent for socket distress signals, to be used at sea. The date of the patent was 1888.

I am wondering if any readers have any knowledge of the Cotton Powder company (now defunct, sadly) who used to
make such socket signals? If so, is there any information as to how bright the detonations were? The patent does not
give which chemical, or amount, was used so I have no idea as to how far such a signal fired, and reaching altitude
could be seen.

With best wishes

Paul
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#2 Mortartube

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Posted 21 February 2008 - 11:02 AM

It closed in 1918 and was in the Faversham area. A little here.

http://www.faversham...?i_PageID=15824

Lots of potential here.

http://www.faversham...?i_PageID=15851

Happy hunting. If I find more, I will post it here.
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#3 Paul Lee

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Posted 21 February 2008 - 11:32 AM

Thanks my friend!

#4 spectrum

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Posted 10 March 2008 - 11:35 PM

Hi everyone,
This is my first post, so please be kind :)
A friend recently sent me a patent for socket distress signals, to be used at sea. The date of the patent was 1888.

I am wondering if any readers have any knowledge of the Cotton Powder company (now defunct, sadly) who used to
make such socket signals? If so, is there any information as to how bright the detonations were? The patent does not
give which chemical, or amount, was used so I have no idea as to how far such a signal fired, and reaching altitude
could be seen.

With best wishes

Paul
--
http://www.paullee.com


I did have some experience disabling rockets similar to those you are describing for a museum 20 years ago.

If the Rockets date from 1888, the propellent would be blackpowder, the range and performance could be judged alongside the larger commercial fireworks, the motors I worked on were blackpowder charged and they dated from the second world war or thereabouts.

The intensity of the payload would not have been as bright as signals of today but not that far off. Magnesium, the most effective light producing fuel used in pyrotechnics was first employed in 1865 and would have been included in the formulation. The best light producing mixtures include Sodium Nitrate as a source of oxygen which, prior to the 1930's, was considered too hygroscopic for general, practical use and thus avoided. The most popular oxidisers prior to this time would have involved Barium Nitrate possibly in combination with Potassium Nitrate.

My guess would be that the payload would have outperformed that of any firework in terms of brightness, I imagine in my minds eye the scene in the film Titanic with the distress rockets launched in their desperate attempts to draw attention to the plight of the vessel and I would say that the depiction in the film would be pretty accurate.

I don't like to speculate on performance, I would say however that such a device would be clearly visible on a clear night from a range of five miles, give or take two, depending on conditions, angle of flight and the vision of the individual. Possibly up to ten.

Interestingly, a distant relative of mine was a survivor of the Titanic and possibly the last person to leap off the vessel. Her name was Bertha Mulvihill and I believe she leapt into lifeboat number 8 which (and I will stand to be corrected) was the last boat to be filled from the ship, she was certainly the last person to land in the boat.

#5 Paul Lee

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Posted 10 March 2008 - 11:41 PM

Hi,
You must have read my mind! I am actually writing about the Titanic for a new ebook that I am writing on the ship and the infamous Californian incident ( http://www.paullee.c...ook_details.php ). Boat 8 was not the last one launched- it was one of the "middling ones", launched between 12.45 and 2.20, when the ship sank. There are speculated timings at http://www.titanicinquiry.com

As for the distance the rockets could be seen... on her way to the disaster site, the rescue ship Carpathia fired rockets, and these
were seen by the Californian. They were seen to be right on the horizon, and were from 15 to 31 miles depending on estimates.

#6 spectrum

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Posted 11 March 2008 - 07:30 AM

Hi,
You must have read my mind! I am actually writing about the Titanic for a new ebook that I am writing on the ship and the infamous Californian incident ( http://www.paullee.c...ook_details.php ). Boat 8 was not the last one launched- it was one of the "middling ones", launched between 12.45 and 2.20, when the ship sank. There are speculated timings at http://www.titanicinquiry.com

As for the distance the rockets could be seen... on her way to the disaster site, the rescue ship Carpathia fired rockets, and these
were seen by the Californian. They were seen to be right on the horizon, and were from 15 to 31 miles depending on estimates.


I am surprised at the distance but certainly wouldn't disbelieve it. It happened on a clear night as I understand and, at sea there would be nothing to interfere with vision so the conditions would be literally perfect. Whether or not you would recognise the effects as that of a rocket could be the subject of some speculation, I would personally imagine that at 20 miles of so (mid point of your estimate) it would appear as an indistince short term glow - if you want to test this out you could recreate something along the lines of the original rocket and fire it somewhere flat.

I would be interested to know if you could confirm the boat on which Bertha Mulvihill escaped.

#7 Paul Lee

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Posted 11 March 2008 - 05:28 PM

I am surprised at the distance but certainly wouldn't disbelieve it. It happened on a clear night as I understand and, at sea there would be nothing to interfere with vision so the conditions would be literally perfect. Whether or not you would recognise the effects as that of a rocket could be the subject of some speculation, I would personally imagine that at 20 miles of so (mid point of your estimate) it would appear as an indistince short term glow - if you want to test this out you could recreate something along the lines of the original rocket and fire it somewhere flat.

I would be interested to know if you could confirm the boat on which Bertha Mulvihill escaped.


Hi,
One thing to note is that on the night of April 14th/15th 1912, the weather was very clear and very cold. There was no moon, no
clouds, and no wind, perfect observing conditions for seeing lights at a distance, and the rockets would reach a maximum height of
860 feet before detonating.
There was an attempt to recreate the rocket firing during a 1996 pilgrimage to the wrecksite. The weather was warm, with a slight
haze. The rockets were not reproductions of the Titanic's distress signals, but still reached about 750 feet. According to radar,
the distance between the firer and the observing ship was of the order of 17 miles...and the rockets were still seen!

As for Bertha Mulvihill, have a look here:
http://www.encyclope...biography/1052/

It seems that she was in boat 15, lowered about 1.35am. This was the furthermost stern boat on the starboard side and was
heavily overloaded; the boats were designed to take about 65 people. This one had 70 in it!

Best wishes

Paul
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Edited by Paul Lee, 11 March 2008 - 05:29 PM.


#8 Paul Lee

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Posted 21 March 2008 - 07:26 PM

Do you know how far such distress rockets could be heard? I am aware that expert opinion says 3-4 miles, but there is an account by
one survivor of the Titanic who said that, at (approx!) 11 miles+, the sound of the detonations sounded like "a cannon" or "guns far off." Another survivor, in a lifeboat only a few miles distant, heard nothing.

Can anyone add any further light?

Many thanks

Paul

#9 Paul Lee

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Posted 20 April 2008 - 11:41 PM

At last I have finished my book. I've managed to prove that simple geometry shows that rockets fired from 21 miles away can be seen, and will attain the same height as the angular width of the full moon. The limiting factor is the brightness of the detonation. I'm also curious about the distance that the sound of the detonation will propagate, but there seems to have been an acoustic masking zone in operation (which might also explain other visual phenomena the night the Titanic went down as a strange mix or humid cold/warm air will extend the range at which objects can be seen over the horizon)

With best wishes

Paul
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#10 icarus

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Posted 22 April 2008 - 12:06 AM

sound can travel incredible distances over water .I take an inflatable dinghy approx 1 mile out turn off the engine and get out a fishing rod . I could clearly hear peoples conversation on the beach . the same happens if at low tide you walk 1-2 miles out across the mud and sand - beach conversations are clearly audible,
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#11 portfire

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Posted 22 April 2008 - 06:44 AM

sound can travel incredible distances over water .I take an inflatable dinghy approx 1 mile out turn off the engine and get out a fishing rod . I could clearly hear peoples conversation on the beach . the same happens if at low tide you walk 1-2 miles out across the mud and sand - beach conversations are clearly audible,


Indeed. The reason being is that the soundwave has nothing to hit. When a soundwave hits an object it's reflected, and is slightly absorbed making the original sound quiter, so if sound has nothing to hit, it can travel great distances.

They used this principle in early radar with giant concrete concave reflectors, with a microphone at the focal point which could rotate on it's axis, and a someone with a set of headphones on. They could hear incoming planes from up to 5 miles.
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