Rickenbacker and Hammond/Leslie sounds

I love Rickenbacker guitars.  They were part of the 60's rock sound (along with Hammond Organs), and that jangle and chime sound is unique to the guitar.  It's an electric semi-hollow body with single coil pickups, and it really shreds in the treble range.

I have been pretty sure for a LONG time that the opening guitar riff to this song was performed on a Rick, just by the sound.  However I only found the video today and verified it :)


The Byrds - a classic Rick band. Roger McGuinn is playing the Rickenbacker at the right. This was the first successful band to fuse folk music with rock music.


Another 1960's band.  What's that John has in his hands?  A Rickenbacker!


And now for the sound of a Hammond B3 or C3 organ, coupled with a Leslie phase shifting speaker.  Think Deep Purple, Booker T. and Keith Emerson (Emerson, Lake, and Palmer)

First of all, the guts of the Leslie speaker:  Below is a video of someone playing an organ into a Leslie 122.  The top part of the cabinet contains a tweeter/midrange speaker and a rotating horn.  Only one side of the horn is hollow and allows sound from the tweeter to escape.  The other is a dummy and just there for rotational balance.  You get the vibrato sound as the opening moves toward you and away from you. 

The same is true of the bottom woofer, but in this case, a rotating cylinder is used, with a port cut in it.  Again, the vibrato sound is created as the opening rotates toward and away from the listener. 

The speaker has a small vacuum tube amplifier inside, and a two speed motor.  The sound is awesome!!


Next up, the Hammond B3/C3 Organ coupled to a Leslie, in the hands of a skilled musician.


These organs have a characteristic growl that is unmistakeable.  Here is Jon Lord doing "Smoke On The Water".  You can easily tell when the Hammond joins the chorus with the guitar :)  Awesome sound!  Solo starts at about 3:00.


Here is Three Dog Night performing a Hammond-y "Out in the Country"  The organ solo starts at about the 2:15 mark.
  

Here is another classic 60's/70s band that used a Hammond/Leslie rig.  The Greg Allman organ solo starts at 3:45, but the entire song is pretty cool, and has a lovely Hammond-filled sound, as well as that awesome dual-guitar sound that the Allman Brothers pioneered. 

What type of music don't I like?

On a more eccentric note, I have been having a blast watching forgotten old music videos.  There are a raft of music videos that everyone has seen.  Then there are those eclectic videos that are nearly forgotten, those are the ones I've been enjoying watching and listening to.

I love pretty much all music.  Classical, Big Band, Punk, Blues, etc etc.  This is just a hodge-podge of fun videos that I wanted to stick up here for the moment.

New Wave!  Devo - one of their less well-known cover songs.  Blows the Rolling Stones away!  "Can't Get me no..." Love the robotic movements!

  Punk.  The Dead Kennedys.  Holiday in Cambodia.  The lyrics to this song crack me up :)

More Punk.  Bad Religion.

Roman Holliday - A little early-1980's swing.

 
Oingo Boingo.  Yep that's Danny Elfman, the acclaimed movie soundtrack producer, back when he was frontman for an offbeat little band.

 

Billy Preston.  I grew up listening to this awesome musician on Top 40 AM radio.   I miss funk music!!!

 

More funk.  The Commodores.   That's Lionel Ritchie on the keyboard :) 

Blues too.  Foghat does the best boogie-woogie version of "Sweet Home Chicago".  The studio version is absolutely awesome, but this live version comes pretty close!  I am a huge fan of slide guitar...

Another awesome slide guitar video.  Roy Rogers.

 
Spanish Guitar also works!  Paco de Lucia and Al DiMeola.

Booker T. and the MG's.  Time is tight.  Just offstage you can see the members of Creedence Clearwater Revival rocking out :)  A couple of these guys were in the Blues Brothers movie.

Dave Brubeck.  Early Modern Jazz

Joe Satriani.  

  

Lindsey Buckingham of Fleetwood Mac soloing Big Love. Awesome accoustic guitar work. 

Miserlou, the classic version

Miserlou, the surf-rock version

Happy (almost) Thanksgiving

...and I'm working, of course.  Haven't had a major holiday off in a couple of years now.  It's not that easy being the newest guy at a facility.  Reminds me of when I was in the Navy, and all the married guys would get cut loose over the holidays.  All the single guys would get stuck babysitting the ship.

A couple of things have come up since my last post.  I read an amazing blog post by a lady who describes the hopelessness of being poor.  Day after day, year after year.  She is highly intelligent and self-aware, and happily, her post has gone viral.  She is hoping to write a book soon, and I would certainly want to read and buy it.

Here is her post.  Go read it now.  She is trying to do good things with her 15 minutes of internet fame.  Awesome lady.

Let's also be thankful for what we have.

The Viola Organista

The Viola Organista was an invention dreamed up by Leonardo da Vinci.  In 1993 and 2004 a couple of these were made.  Now we have some great video of a man who built one and performed a concert.  Below is the original drawing that Leonardo made over 500 years ago.

A Polish master instrument maker used the drawing as a basis for making the third ever Viola Organista.  It uses rotating drums, wrapped with horse hair, as sort of an endless violin bow.  The strings are pressed down onto the rotating drum when the key is pressed. 

The thing sounds like the entire string section of an orchestra!  It's really neat. 

Music starts at about 4:00, and English subtitles are available by clicking "CC" at the bottom right, if you are interested in the interview part.



Below, the first time this instrument was ever heard in public.

Belated Veteran's Day Post

My daughter's school once again held a Veteran's Day assembly, where any veteran they knew was invited to attend, and honored.  Again, it was nice to have the service of country be acknowledged.

The transition from military to civilian can be pretty easy, or it can be difficult.  Coming out of the submarine service, I had a little bit of difficulty.  I missed the intensity of running casualty drills, of the camraderie, and also with the return from isolation from the public.

My own service was not what I wanted to post about for Veteran's Day though.  This guy is.

The Northern Garage

A family member recently moved nearby, and I promised that we would insulate and drywall the garage for them, if they would pay for the materials.  The garage was quite cold and drafty, as the eaves are vented into the attic space on three of the walls.

I bought and installed a new garage door opener as a gift.  I also purchased (but have not yet installed) a couple of fluorescent fixtures to replace the bare 100W bulbs.

Having now completed the work, I can state with authority that I would rather be unemployed and hungry than be a drywall installer.

Below are two pictures taken of the garage before we started the work.

 

Below are pictures I took of our handiwork afterwards.  Fortunately it was "just a garage", so the finished look wasn't too much of an issue.



I added an access hatch to the garage attic, although I wasn't sure that it was necessary.

 The garage door opener is a belt-drive type.  It is unbelievably quiet!

 Below is a video comparing chain and belt drives.  I think I will be installing these in my own garage pretty soon :)

Motorcycle Racing

I am a huge fan of motorcycle racing.  There is a great history of racing, going clear back to the wooden-tracked velodromes in the early part of the last century.

I am fascinated by the technology that is created to get a little extra speed.  Below is a Honda six-cylinder Double Overhead Cam motorcycle with only 125cc of displacement!

 

The other fascination I have is just how fast these guys go in the modern era.  Today there are two major types of road racing that I enjoy watching. 

 

The first type of race, MotoGP (Previously known as Grand Prix), takes place on custom-made race tracks, with prototype motorcycles.  These are the fastest race bikes on the planet.  No part of the motorcycle is allowed to have anything in common with a street bike.  The tracks in MotoGP are as safe as they can be made, having plenty of run-off room, and no obstacles to collide with.  In addition, the tracks are usually pretty short, allowing the riders to learn them pretty quickly and master them.

 

Because MotoGP bikes are prototypes, they are allowed to use electronic traction control, wheelie control, and specialized tires, all of which contribute to insane lean angles and fast lap times.  To a certain extent, a rider can open the throttle, and the onboard computer will decide whether to allow the engine to make more power based on rear wheelspin and cornering angle.

 

It's impressive to see what these machines are capable of.  Motorcycle action starts at about the 0:30 mark in the video below.

  

The other type of road race... is the Road Race!  These guys are just crazy.  I believe this type of racing is only still done in Ireland.  Bear in mind that if these guys crash, it's likely that they will hit a tree, block wall, curb, or other unfriendly object.  Needless to say the injury and death rate for this type of race is quite a bit higher than for MotoGP.  Not just for the riders, but for the fans.  Crowds are allowed right up to the race course.  I am sure it's very intense to be a spectator.

Possibly the most famous true Road Racing course is the Isle of Man TT, which is a six lap run around a 26 mile-long circuit on an island.  The Isle of Man isn't quite as crazy as the above race, because for the Isle of Man, they use a staggered start, and takes each rider's lap time. 

However because the Isle of Man is such a long course, utter concentration is required every moment of every lap, or the rider can easily be killed.


I will do some other posts about the role of technology in the bikes over the decades, and how each invention has helped squeeze a little more speed (or improve braking and handling) to get where we are now.

TRIGA - an amazingly safe nuclear research reactor

So far we have talked about natural reactors, fast neutron reactors, plutonium production reactors, and thermal power plant reactors.

There is one cool reactor that I would be remiss in discussing, and that is the TRIGA reactor.  I worked at a facility where two of these were located, and was licensed to operate them both.  One was the very first TRIGA reactor ever built, rated at 250 KW (thermal), and the other was a MK IV model, rated at 1.5 MW (thermal).  These reactors are swimming-pool reactors, and so they don't generate steam or electrical power using steam turbines.

In fact TRIGA stands for (T)raining, (R)esearch, (I)sotope production, (GA) General Atomic, the manufacturer.

In the late 1950's there was a desire to promote "Atoms for Peace".  This was Eisenhower's attempt to invoke the power of the atom for peaceful purposes.  The world was understandably horrified by the images of Hiroshima and Nagasaki, as well as the possibility that the budding cold war might turn into a hot war at some point.

The invention of TRIGA reactors went a long way toward fulfilling that vision.  Unlike other reactors, TRIGA reactors have a solid moderator that is cast into the fuel itself.  Therefore there is a homogenous blend of solid moderator and fuel.  The moderator is Zirconium Hydride, and as you would expect, the hydrogen atoms do the moderating. 

Because about 60% of the moderator is solid and homogenous with the fuel, this reactor has what is known as a "prompt negative temperature coefficient of reactivity".  In other words, the very instant a runaway nuclear reaction begins and starts causing fuel temperature to increase, the solid moderator temperature also instantly increases, which in turn reduces the available thermal neutrons.  This provides a VERY rapid damping of the runaway nuclear reaction. 

If you recall in an earlier post, it is important (in all reactors except TRIGA) to never allow the reactor to be critical on prompt neutrons alone, because each generation of neutrons only last 10^-14 seconds.  There is no way to control a reaction that proceeds so quickly, so the small fraction of delayed neutrons are what allow us to control reactors.  Chernobyl, SL-1, and the Borax Experiment were each prompt criticality events that ended badly.

TRIGA reactors though, can easily tolerate a prompt critical event.  Doing this is called "Pulsing" the reactor. Any reactor can be pulsed, but only a TRIGA can do it more than once ;)  In fact, the record reactivity insertion into any reactor was  TRIGA, at 5.22 times the value needed to be prompt critical.  Because the moderator heats up as rapidly as the fuel, it shuts the reactor down just as soon as heat is generated, in a few thousandths of a second, without operator intervention.

TRIGA reactors ended up being sold around the world.   Being low-power, they weren't practical for making weapons, and the solid UZrH moderator was incredibly difficult to extract from the fissionable fuel, so using the fuel for making weapons was not possible.  Even so, currently manufactured TRIGA fuel has been reduced from 20% U-235 down to 7% to prevent proliferation.

Here is a video of a TRIGA reactor being pulsed to 2.5 x prompt criticality.  Any other reactor would vaporize the fuel and create a steam explosion, blowing water upwards out of the tank!



Below is an image of a TRIGA reactor at the bottom of the pool, while not in operation.  As you can see, it's quite simple.  The fuel elements rest on a bottom grid plate, and are kept vertical by the upper grid plate.  The fuel can be grabbed by a long-handled pole with a ball-type coupler at the end, similar to how modern hydraulic couplings work.

The rods sticking down into the core are just aluminum shafts that connect the drive motors to the control rods (which are partially out of the core).

The inner ring around the core is a lazy susan.  Samples can be dropped into a number of holders in this dry ring.  When the reactor is in operation, the ring rotates to ensure each sample is exposed to equal amounts of neutron flux.  This is useful for performing neutron activation analysis on several samples at once.

The outer ring is a graphite reflector/moderator, which reduces the amount of fuel needed.  The cans outside the reflector are neutron detectors, for determining what power level the reactor is at.  The little lanyard at the bottom is attached to a neutron source (usually Americium/Beryllium).  This makes sure there are enough neutrons available to start the reactor up.  Also its a daily test to pull it and stick it next to each neutron detector and make sure they work OK before you start the reactor up.

The reactor with a hole in its head...

In 2002 the US came very close to having a massive loss of coolant accident that probably would have led to major core melting (melt-down), and a release of offsite contamination.  Everyone knows about the meltdown at Three Mile Island, but not many people know about this...

Background:
In a Pressurized Water Reactor (PWR), the control rods are completely removed from the core after the reactor is up to full power, and dilute Boric Acid (a strong neutron poison) is carefully added to control reactivity.  

The purpose of this process is to achieve a flatter neutron flux profile throughout the core. 

A flat neutron flux is desirable for a couple of reasons:  It helps to even out fuel burnup and it helps to reduce hot and cold coolant channels.  When control rods are partially inserted into an operating reactor core, neutron flux is depressed near them, since they absorb neutrons.  Therefore fewer fissions occur near the control rods.  This localized reduction of fission causes uneven fuel burn and creates cold zones due to reduced fission near the rods.  For a given power output, other sections of the reactor core away from the control rods must now run hotter to compensate.

Below, a side-view of a reactor core.  The solid line indicates neutron population in this reactor at steady-state power, with a control rod partially inserted to control reactor power.  Because there are very few neutrons in the area adjacent to the control rod, for a given power level, other areas of the core have to produce more fissions.  The spots on the solid line marked "A" are those places where we might see excessive fissions, overheating, and possible fuel element failures.

The dashed line indicates neutron population with the control rod removed (which is possible if you add Boric Acid as a virtual liquid control rod).  As you can see, neutron population is more consistent throughout the reactor, and therefore there won't be any excessive localized fission and heating, as you see at the points marked "A"

With borated primary coolant, neutrons are depressed equally throughout the core, and so power generation is more evenly distributed, and the reactor can be run closer to its thermal limit, because there is no need to account for hot and cold zones due to tilting of the neutron flux.

However you would hope that there is a better way to keep a flat neutron flux profile throughout a reactor core than using very hot diluted boric acid in the primary coolant loop.

As mentioned above, the primary coolant in these PWR reactors contains Boric Acid, which is a mild acid.  For this reason, the piping, pumps, valves, etc are all made of high chrome steel (stainless steel).

The reactor vessel and closure head, however, are not.  Due to their size, it is impractical to make the entire thing from stainless steel.  Instead, the reactor vessel and head are made from carbon steel, and their interior is clad with a sheet of 3/8" thick stainless steel.  In this way, the carbon steel, which is not resistant to acids, is protected from contact with the Boric Acid in the primary coolant.
 
The Event:
In 2002, Davis-Besse nuclear power plant in Ohio discovered they had a very minor primary coolant leak. The coolant was leaking out along a penetration in the reactor vessel head, where a Control Rod Drive Mechanism (CRDM) was mounted.  The CRDM is what pulls the control rods out of the core and allows the reactor to start and shut down.  The coolant leak was so minor that it hadn't been noticed - in a million gallon system, a minor leak can go undetected almost forever.  Any water leaking from the primary coolant would also be quite hot and would flash to steam immediately, so no water puddling would occur.


Davis-Besse had a tiny coolant leak, however.  One which they were unaware of.  In 2002 the plant shut down for a refueling outage, and performed an inspection underneath the insulation on the reactor vessel head.  This was done after other plants of the same design had uncovered minor leakage.  They found a little problem...

At the time it was discovered, the acid had eaten away a hole the size of a football completely through the reactor vessel head in the area of the leaking CRDM penetration.  The only thing that was holding the 2500 psig primary coolant in place was 3/8" of stainless steel cladding, which was bulging outwards from the pressure. 

Below is a picture of a Babcock & Wilcox design PWR primary coolant loop, with the reactor vessel head highlighted.

 Below is a cut-away of a B&W reactor vessel head, with a zoom-in on the point of the leak.

Below are images of the hole in the reactor vessel head.

The photo below gives you an idea how thick engineers designed the reactor vessel head to keep 2500 psig of primary coolant in place.  It's astonishing (and wonderful) that thin piece of 3/8" of stainless steel was able to keep the coolant from blasting out.

This would not have been merely a primary coolant leak.  This would have been a major accident.  Here are some of the potential consequences of such a massive leak, had the cladding ruptured:

1. A massive steam/water jet would have blasted out of this hole, certainly damaging this control rod, but possibly adjacent ones also.  Could the ability of the reactor to shut down been compromised?
2. The steam/water blast probably would have ripped tons of insulation loose.  This would have fouled the intake of the emergency water re-injection system, which takes suction from the floor of the containment building.
3. Major coolant leak accidents are typically modeled for weaker points in the primary coolant system - pumps, steam generators, drain lines, etc.  These are equipped with remote-operated valves to isolate these leaks from the reactor core.  This leak was was directly above the reactor core, and not isolable from it.  Continuous water injection directly into the core would be required for several months to prevent decay heat from melting it.
4. It is very likely that with the reactor fill system compromised due to ingesting insulation, and an unisolable leak right above the fuel, that core damage would have occurred.

In the end it took a couple of years to manufacture a replacement head and get the plant back online.  

Odd Quirks About Nuclear Reactors - Criticality Accidents

One quirky thing about nuclear reactors:  If you are not careful - particularly with Plutonium - it is possible to create a reactor unintentionally.  That is, you can inadvertently assemble enough fissile material to start a chain reaction, outside of the safe confinement of a shielded reactor vessel.