You know you might be overdoing arcane interests when you get strange dreams on the topic... :-)
--------------------------- While visiting Britain my sister bought a fairly technical book on the Spitfire at the IWM for Christmas and I've been reading it, but it's not related to WW1 rotaries or lawnmowers.
She also caught Covid there.
Well , I wouldn't call my dreams about guns "strange" ... disturbing maybe . But not strange .
Did you know that a Harley 45° V-twin is actually a partial radial engine ?
Black rain!
Is everywhere and endemic now. I assumed I must have had it without symptoms having worked all the way through covid19 pandemic - then a year ago got something which really left me flattened for a week which was covid. Had to stay warm under two duvets to mitigate the discomfort of it. It clearly mutates "like mad" so comes in waves as variants evade natural immunity to previousl strains. We are getting "normal" "colds" again - streaming but only for a day or so. Immune systems back up and running after the "lockdowns" which if prolonged would have themselves lead to higher mortality. Everyone without honed immunity and when a virus does break through it would be at the worst time, likely mid-winter, and we would have had the huge wave of serious illness and mortality we sought to avoid. Looking back - slowing the initial propagation, at huge effort, was a good idea. Turning it into a "Wow this is good - let's do it for ever" was manifestation of general pervasive institutional stupidity.
Hope she enjoyed time in England / Britain.
I remember a couple of disturbed dreams during my doctoral years.
In one I was on holiday in Yugoslavia - was during the break-up. Given I fondly remember Yugoslavia. I was crawling between rocks try to admire some monastry or something like that while bullets went overhead.
In another I was in a laboratory which was all brown dark and dusty, hopelessly cramped so you could only move sideways in some places and the floor kept collapsing - your foot kept going through the floorboards.
It is plausible that these were connected to what was happening. The situation was politically tense during my research.
The workshops were a mess. Only had to be gone a few days and every machine was - well, motors and things ran, but saw blades had not a tooth left due to misuse, coolant was run-out and the machines were jammed-full of swarf, etc. I'd have to do a lot of "housekeeping", refill soluable-oil coolants - and get out my own sawblades to do the proper cuts through a lot of plate steel (then put the toothless on back in - they'd reduce a good blade to the same state in minutes to an hour anyway).
The exhaust has thick liquidy raining-down hydrocarbon residues?
Did you know that a Harley 45° V-twin is actually a partial radial engine ? Snag
------------------------ Sort of. The forked connecting rod puts both cylinders in the same plane, but the V-12 Merlin is built that way too. A real radial has one master connecting rod that rides on the crank pin and the other rod "big ends" are on pins around it.
I saw a one cylinder, 4-stroke Saito FA-80 model engine at a flea market and examined it until the seller dropped the price to $30. At that price it doesn't have to run, just sit on a shelf with other curios.
Often while I was in the shower and couldn't write it down immediately.
I found that link while researching song inspirations, Pattie Boyd was the subject of quite a few. In the 60's I was the tech/roadie for a film maker who was doing music videos so I saw something of the off stage lives of musicians on tour, and was happy -not- to be one. His studio partly imitated Warhol's Factory, minus the drugs.
I remember a couple of disturbed dreams during my doctoral years.
In one I was on holiday in Yugoslavia - was during the break-up. Given I fondly remember Yugoslavia. I was crawling between rocks try to admire some monastry or something like that while bullets went overhead.
In another I was in a laboratory which was all brown dark and dusty, hopelessly cramped so you could only move sideways in some places and the floor kept collapsing - your foot kept going through the floorboards.
It is plausible that these were connected to what was happening. The situation was politically tense during my research.
The workshops were a mess. Only had to be gone a few days and every machine was - well, motors and things ran, but saw blades had not a tooth left due to misuse, coolant was run-out and the machines were jammed-full of swarf, etc. I'd have to do a lot of "housekeeping", refill soluable-oil coolants - and get out my own sawblades to do the proper cuts through a lot of plate steel (then put the toothless on back in - they'd reduce a good blade to the same state in minutes to an hour anyway).
------------------------------ The Goes Wrong Show. I was put in charge of an open-access company model shop that fit that description. You can't cut a rotary lawnmower blade on a bandsaw at woodcutting speed, though someone kept trying. The gearbox was broken so I couldn't drop it to the lowest speed. Fortunately the electrical engineers didn't understand and weren't tempted to abuse the other machines.
In the sci-fi novel The Mote in God's Eye the aliens show the Earthlings a museum of technology, in which the chief engineer notices that everything is defective. It's a test of mechanical aptitude, which for the aliens classifies one as Aspergic with no interpersonal skills. They are amazed that he can also function as a supervisor. As an electronic technician I had to be careful to not slip into that bin, thus my exposure to the arts.
The workshops were a mess. Only had to be gone a few days and every machine was - well, motors and things ran, but saw blades had not a tooth left due to misuse, coolant was run-out and the machines were jammed-full of swarf, etc. I'd have to do a lot of "housekeeping", refill soluable-oil coolants - and get out my own sawblades to do the proper cuts through a lot of plate steel (then put the toothless on back in - they'd reduce a good blade to the same state in minutes to an hour anyway).
--------------------------- I bought a how-to book, whose title I apparently don't remember well enough for Google, that turned out to be a British socialist fantasy of communal ownership of all lawn and garden equipment, to avoid the alleged waste of everyone buying their own. I suspect it was written out of frustration that the neighbors had learned not to lend anything to the author.
That's SO neat! So out-of-the-box! An air compressor with no rotating parts.
One of the best features: the air pressure is independent of the head of the water power source. The air pressure is determined by the depth of shaft that the compressor is housed in. The head determines the flow & power, but not the pressure.
I put another small doc here (5 images) about the Victoria Mine installation. It's from scraps I picked up from a friend in the area:
That's SO neat! So out-of-the-box! An air compressor with no rotating parts.
-----------------------------
The same principle creates vacuum.
A jet of steam sucking in water can raise the water's velocity and kinetic energy high enough to force open a check valve into the boiler that provided the steam, thus it's a feed pump with no moving parts except the control valves.
Thanks. It was interesting, but missing some referenced figures. So I went looking for the article. I found it here:
On 17/12/2023 23:24, Bob La Londe wrote: [...]
Urea itself is not explosive, and is seldom used in explosives, though it is sometimes added in small proportions to ANFO to prevent noxious gases when eg pyrite is present.
Urea nitrate is sometimes used in home made explosives, but it is not used in any civil explosives I know of, or for blasting purposes - that's mostly the province of ANFO and water gels, with gelignites and dynamites occasionally used on smaller scales and for demolition work.
Water gels and emulsion explosives are typically mixed on-site from ammonium nitrate solutions plus fuels. They are usually not cap-sensitive, though cap-sensitive ones do exist, and need a booster explosive charge to detonate. The non-cap-sensitive ones are easier to transport.
ANFO is also often made on site. Ammonium nitrate prills come in two types, in one the prills are carefully engineered so that they will absorb exactly the right amount of fuel oil if they are to be used in ANFO explosives, and in the other they are engineered so they won't absorb fuel oil if the AN is to be used as fertiliser.
Sorry, I don't have any practical experience in blasting tunnels. You do usually need higher velocity explosives like dynamite or gelignite for hard rocks though.
Peter Fairbrother
Thanks for that. Since I posted this question I have learned a lot.
The "traditional" blasting medium used in Cornwall was gelignite. I've had comment that cost would make you have second thoughts about doing that to conform with tradition. Brings ANFO to the fore now. I've read about "emulsion". Seems is "the business" when you have a big tanker driving around pouring into many big blasting holes. "per-unit" cost very favourable - but the costs of maintaining a storage of "ANBI", pumps to safely handle ANBI, etc. - the set-up and maintenance costs - might have you looking at ANFO (?)
I have a lot more learning to do. Couple of articles recommended here which I am reading. Wanted to post something along the lines of "Wow!" in that what was unintelligible before now in the main makes sense. Will continue to read and learn in other ways then report back.
The granite I met here is so hard that a powerful rock-drill (percussion plus rotation) could not drill with a four-cutting-tips cutter - had to revert back to a carbide-tipped chisel-edge drill.
Implies that need a goodly blasting medium.
Anyway, hopefully will be back here soon.
Rich S
The granite I met here is so hard that a powerful rock-drill (percussion plus rotation) could not drill with a four-cutting-tips cutter - had to revert back to a carbide-tipped chisel-edge drill.
Implies that need a goodly blasting medium.
Anyway, hopefully will be back here soon.
Rich S
------------------------ With my drill NH granite cuts faster by starting with a 1/2" bit. "Fast" is relative, at least I can see it move.
By Hiram Maxim's brother:
I had access to two "scrap books" from the Victoria Mine for a short period a long time ago and scanned them. It had all sorts of compiled news articles, ephemera concerning the mine. They were all clippings in various shapes and not always easy to decipher how they originally went together. I likely have the "missing" items just didn't know where they belonged🤷
I used to vacation in the area and collected several more recent books on the subject along with other odds & ends. It was a long time ago...
Yes, it is more expensive. As is NG-dynamite. However they are about twice as powerful as ANFO, so you need less.
I'm unsure whether the AN used in ANFO is itself an ANBI - if AN is prilled for explosives purposes it might well be. Or perhaps it is controlled under one of the many AN control orders, which I have only a passing familiarity with.
However there is another problem or three with ANFOs, AN water gels and emulsions - they need bigger holes than NG-dynamites or gelignites, as they will not explode properly when the diameter of the hole is small.
In practice, combined with the fact that they are only about half as powerful, you end up using a lot more. Which means a lot more nasty gases to get out of your tunnel.
Second, they really need boosters. There are cap-sensitive gels and emulsions, but then you are getting into the same legal hassles as the higher velocity explosives - plus you need different certificates and licenses for the boosters. Some people use detcord as a booster, but the same requirement for an explosives certificate etc applies (in the UK).
Third, and perhaps most important, especially when used for tunnels in hard rock, they aren't really brisant enough to cope with hard granite. The NG-based (or NC-based) high velocity explosives produce shock waves which will fracture granite, but the lower velocity of detonation of the AN-based explosives give more of a hard push than a breaking shock.
Indeed. Gelignite, or a NG-dynamite, seems called for.
Also, for a a small tunnel, AN-based explosives are generally less useful - though they do make small diameter cap-sensitive AN emulsions, AN-based explosives are generally better for larger charges.
You didn't say how long the tunnel is, but unless it is very long jelly/NG might even be cheaper. It will certainly be more practical and need less drilling.
BTW, Cranfield sometimes do a short course on mining explosives.
Peter Fairbrother
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