Larry:
I've watched your posts for awhile now and suspected that you had a story to
tell. Thanks for the background candor. We now know who to bug
Dan
"Larry W4CSC" wrote in message
...
On 27 Nov 2003 03:10:51 GMT, pamdump (Den73740)
wrote:


I learned a lot working for NOAA, I was an oceanographic tech for 25
years and
spent a lot of time hooking up instruments to a shipboard scientific
computer
system that started out with DEC/VAX and over the years evolved into Win
2000.
There was a lot of trial and error.

Great job. While I worked for Tracor, the marine division brought
their SEACON sea construction barge into St Julien's Creek Annex, the
old Navy ammo dump, in Norfolk. Electronics Systems Division
installed an extensive alarm system for fire/flood/intrusion aboard
her, even with a 250W paging transmitter with antenna atop the mast to
alarm crew that was ashore in Diego Garcia resort island she was
headed for.

Your DEC/VAX reminded me of her station keeping system which had a
PDP-8 mini tending 4 sonar pingers shot into the bottom over her work
site. It was tape programmed, as I remembered. The barge had the
queerest propulsion system I ever saw consisting of three diesel
engines driving hydraulic pumps which, in turn, drove "egg beaters"
that rotated, two under her stern and one under her bow to keep her
going up to 6 knots in ANY direction. Most impressive when we took
her out for a little sea trial/company party before she left.

Wonder where she is now?....(c;

I was hoping there was some school that could give me a good background
in
setting up and interfacing all these different manufacturers of boating
electronics equipment, satellite gear setup, and GMDSS maintainer.

I got an FCC 1st Phone with RADAR endorsement way back when you had to
WRITE the test to the satisfaction of the FCC engineer giving it to
you. The last one is still in its nice frame over my desk. The GROL,
a meaningless piece of paper they give away to almost anyone capable
of memorizing the test questions they also give away, is stashed in a
drawer to hide it.

I took the GMDSS operator and GMDSS maintainer tests this year. I
found the tests, as with all new FCC tests, a simple matter of rote
memorizing stupid questions about subjects and regulations you would
LOOK UP, not memorize, in the real world. It's almost as if they're
afraid not enough poorly educated public school students, unskilled in
math and science today, couldn't pass them. So, they make it a terms
and symantics test.....

I passed so now I can work on the same marine crap I've been working
on but now with GMDSS aboard. A volunteer examiner, who used to be
one of the most illegal CBers in South Carolina, administered the
test. You can download the test question bank from the FCC website:
http://wireless.fcc.gov/commoperators/dm.html
That'll hook you to the maintainer's license. Click on the operator's
license on the left panel to go over there. Good luck with the tests.
It's not rocket science.

I'm still getting paid, just not as much :}


I get paid, occasionally, doing mostly installations and networking it
all together after someone has screwed it all up. For my boater
friends, of course, I don't. I get to go to sea with them.....which,
to me, is worth far more. I've just helped an English friend restore
and fit out an '85 Amel Sharki 41 ketch with all the electronic toys.
Plans are to leave in March for the Bahamas and stay, arriving in
Daytona Beach for the race from there to Charleston, our home port, on
May 25th. Then, we plan on doing the Charleston to Bermuda race.
From Bermuda, things get a little muddy. He just retired from a very
profitable job where he still is depended on for consulting work. He
keeps talking about sailing from Bermuda to England and home over the
Summer before returning to Charleston in the Fall. I may just close
my business if that happens. I'm semi-retired, myself, but not
financially secure like he is. We've really enjoyed working together
on "Lionheart" since last August.....(c; He refers to me as his
"Chief Engineer"....




Larry W4CSC

NNNN

Larry W4CSC wrote:

Your DEC/VAX reminded me of her station keeping system which had a
PDP-8 mini tending 4 sonar pingers shot into the bottom over her work
site. It was tape programmed, as I remembered.

Instant flashback! In the late 70's we used a PDP-8 for submersible
tracking by laying an acoustic transponder array, calibrating its
position in UTM's and then tracking another acoustic transponder mounted
on the vehicle. The runs were recorded in real time on a pen plotter.

The PDP was tape programmed. Remember the nightmare of dropping a roll
on the deck? We used to make corrections and enter new parameters by
using the front panel switches which took hours sometimes. Incredibly
primitive by today's standards but that system replaced a Decca unit,
Omega, a surveyor and hours of post processing.

Rick

On Thu, 27 Nov 2003 17:08:42 GMT, Rick
wrote:

Larry W4CSC wrote:

Your DEC/VAX reminded me of her station keeping system which had a
PDP-8 mini tending 4 sonar pingers shot into the bottom over her work
site. It was tape programmed, as I remembered.

Instant flashback! In the late 70's we used a PDP-8 for submersible
tracking by laying an acoustic transponder array, calibrating its
position in UTM's and then tracking another acoustic transponder mounted
on the vehicle. The runs were recorded in real time on a pen plotter.

That's about how SEACON station keeping worked. When the current
dragged the barge off the center of the pinger, the sensor array
noticed the pinger drifting and the PDP-8 moved the constantly-running
propulsion controls so it would remain over the target pinger until
its battery went dead, when they shot down another pinger.

The barge had a huge crane on an elevated track along port and
starboard gunwales that went from the stern to the stack, even over
this big "garage" with an aft-facing rollup door. The deck inside the
garage and aft towards the stern could be removed by the crane so
divers and equipment could be lowered straight down into the abyss,
keeping the waves off it and allowing large loads to be lowered from
the deck without listing the barge. It was a beautiful arrangement.

Her only problem was she went 6 knots, in any direction, but only 6
knots wide open. They towed her to her work location with a long line
and seagoing tugboat so she'd arrive before everyone on board
retired...(c;

It's quite a sight to see her turn perfectly on her central vertical
axis, without the current pulling her away in the process. The old
PDP-8 did a good job, I suppose.

That was about 1980ish. Wonder where she is now?



The PDP was tape programmed. Remember the nightmare of dropping a roll
on the deck? We used to make corrections and enter new parameters by
using the front panel switches which took hours sometimes. Incredibly
primitive by today's standards but that system replaced a Decca unit,
Omega, a surveyor and hours of post processing.

Rick


Larry W4CSC

NNNN

Larry W4CSC wrote:

It's quite a sight to see her turn perfectly on her central vertical
axis, without the current pulling her away in the process. The old
PDP-8 did a good job, I suppose.

Spent quite a bit of time on a dynamically positioned drillship in the
Med and West Africa and off Labrador. It used a Honeywell DP system to
maintain position over a wellhead more than 5000 feet below.

The system used acoustic transponders and a "riser angle" input to
control the ships screws and 4 retractable thrusters and could maintain
position within about a 50 feet circle in Winter open ocean conditions
between Labrador and Greenland. It was an amazing system for its time.

The DP operator could bypass the computers and use a joystick and a
polar display to move the ship manually. This was used whenever we
reentered the drill hole during initial drilling ops.

I was a submersible pilot we and would sit on the bottom (down to 5800
feet) and visually direct the DP operator to move Xx feet XXX degrees
and then DROP when the drill bit was located above the guidebase.

Rick

There's some amazing technology out there. Thanks for the post!

On Sat, 29 Nov 2003 04:15:38 GMT, Rick
wrote:

Larry W4CSC wrote:

It's quite a sight to see her turn perfectly on her central vertical
axis, without the current pulling her away in the process. The old
PDP-8 did a good job, I suppose.

Spent quite a bit of time on a dynamically positioned drillship in the
Med and West Africa and off Labrador. It used a Honeywell DP system to
maintain position over a wellhead more than 5000 feet below.

The system used acoustic transponders and a "riser angle" input to
control the ships screws and 4 retractable thrusters and could maintain
position within about a 50 feet circle in Winter open ocean conditions
between Labrador and Greenland. It was an amazing system for its time.

The DP operator could bypass the computers and use a joystick and a
polar display to move the ship manually. This was used whenever we
reentered the drill hole during initial drilling ops.

I was a submersible pilot we and would sit on the bottom (down to 5800
feet) and visually direct the DP operator to move Xx feet XXX degrees
and then DROP when the drill bit was located above the guidebase.

Rick


Larry W4CSC

NNNN