UPDATES on Building the 7" Treble-Banded Brooke Rifle by Seacoast Artillery

[seacoastartillery]

      About two months ago Rampa Room Rick asked us for an update with our build of the 7" Brooke.  We had nothing new at that time, but now we  have a new series of pics that form this update.  They are very similar to a few that we have shown before back in '08, but these are production process pics and not prototype method photos.  These photos show how a 30 pound block of 4150 0rdnance steel becomes a ‘Trunnion Ring’ which weighs 4.5 pounds.  CSN Commander John M. Brooke designed this 20,000 pound plus rifle to be an "Ironclad Killer".  His range testing proved that if Confederate Artillerymen could catch a Federal Monitor within 800 yards that they could penetrate it's 8" of wrought iron armor.  So, he figured that the recoil impulse on this powerful rifle would be stout and he designed a popular substitute for the traditional, cast iron trunnion.  It was a combination of an applied 'Trunnion Ring', ‘Trunnion Yoke’ and a 'Breech Strap' that held the ring in position. 
 
      Artillery Officers of the Confederate 'Siege Train' surrounding Charleston's Harbor spoke highly of this design in their,  “Condition of the Ordnance”, surveys and reports.  As they saw it, the Brooke breech strap  was useful on two counts.  It provided insurance against failure during extreme tension loads, (firing) and also it provided support where heavily-stressed, banded rifles needed it most, in the breech area.  You see it was their valuable observation that most of the failures of these rifles occurred, not in the area of the reinforcing hoops, but rather at the breech, itself.

These are about ½ the photos available; the remainder will be posted, after organization, tomorrow.

Tracy and Mike

 
The 30 Lb. bandsawed Trunnion Ring blank spins at 375 RPM as one of it’s square trunnions is turned cylindrical.  The other end has a ‘Lathe Dog’ jig attached which connects the workpiece spinning on centers to the rotating chuck.




The lathe dog and one center are removed and the part’s ends are swapped.  The 3 jaw holds the turned trunnion and the other, still square, is now ready to be turned.




  On this slightly fuzzy pic of our prototype, you can see the front sight mass which is integral with the Trunnion Ring.  Also there are two rectangular bosses on the back edge of the ring.  These need corresponding  notches in the second largest reinforcing hoop set.  These guarantee ‘clocking’ of the trunnions, themselves.




The largest reinforcing hoop set is clamped tightly to stop movement during critical notch machining and chiseling.




  A 50 Millionths test indicator and stacks of one-two-three blocks are used to get the center of the largest reinforce on the exact tube centerline.




‘Centering’ from the muzzle. 




A machinist’s view.

[RocklockI]

I'm not sure what that blue whirl is ,BUT it is amazing knowing that that big rough ugly second picture becomes the the 'band' that the trunion are located on in the third pic. ......
 
BTW did this thing have trunion caps ?    
 
 

[seacoastartillery]

 

I'm not sure what that blue whirl is ,BUT it is amazing knowing that that big rough ugly second picture becomes the the 'band' that the trunion are located on in the third pic. ......
 
 BTW did this thing have trunion caps ?     

      The blue swirl is the dried Dykem, layout fluid on the backside, visible as it rotates CCW for trunnion turning.  Just drill a bigger and bigger hole and then bore it until you have it big enough to slide on the tube.  Oh don't forget the taper as well.  (Trunion Caps??)  I know that this common misnomer is used intentionally here by Gilligan.  He knows that it's one of my pet peeves that otherwise reasonable people cannot remember the real name of this piece of artillery carriage hardware.  The answer to his question is this:  No, most seacoast guns, including the 7" Brooke Rifle do not use 'Cap Squares' to hold the trunnions (two 'n's Gilligan), and the tube securely in the carriage.  Gravity holds these extremely heavy tubes in place.  Heavy naval gun carriages use cap squares because of the lurching gun mounts in a blow. 
 
 Below are a few more pics which show progress on the 'Trunnion Rings' used on the treble-banded Brooke.
 
 Mike and Tracy
 
 
 This shot shows the rectangular 'clocking bosses' projecting up from the ring's face between the clamps far and near.
 
 
 
 
 The 'Front Sight Mass' is machined by a 3/16" ball end mill in a 5" extension holder from the right angle milling attachment. The ball shaped tip only rotates. The work being machined moves up and down and rotates around the 'W' axis (via motion of the rotary table) as it is machined.
 
 
 
 
 The area for the notch is marked with black marker and it's width and depth is scribed.  It is milled with a 3/16" std. carbide end mill.  The depth is machine .005" oversize and the sides are cut .002" undersize to prepare for final fit via sharp chisels.
 
 
 
 
 After machining, but before chiseling, this is what the 'clocking boss recess' looks like.
 
 
 
 
 The second recess is milled.  The mating part is moved into position and the notch location and limits are scribed on the reinforce face.
 
 
 
 
 A hardened chisel is held in a shop-made holder in the milling machine's quill.  Very little downward pressure is required if your chisel is sharp.  The purpose of this method of material removal is to simply to 'square' off the end milled corners.
 
 
 
 
 An end view of the chisel and the notch to be squared.
 
 
 
 
 Actual chiseling of very tough steel, 4150 Rc 32.   .0003" thick flakes fall to the center of the notch and are whisked away.
 
 

[RocklockI]

no cap squares , hummmm    . Do you remember your time at the oar ? You know iirc I actually let you have some water last time .
 
I'm kind and have been kind ,yea benevelent to you as low man on the on the crew list .
 
And you turn on me ...!
 
My wife has been with us three times this year and has seen what needs to be done and does it .... she is a crew member . We have no sightseers except ...... 
 
You say you have two trunions ? Are they yours ?......both of them ?
Gary
 
 

[seacoastartillery]

     

no cap squares , hummmm     
 
And you turn on me ...!
 
Gary       

     Turn on you?  I thought I did pretty well what with sailing within two points of directly into the wind in order to get out of the shallow part of the lake were we ended up repeatedly.  We ran with the wind quite a bit as I recall.  What about taking repeated soundings with the big, round lead weight and knotted line.  I allowed you to explore the shoals safely and I must say your sailing was excellent that time you brought us so close to shore I believe that I could feel the hot breath of Bovines that lined the bank of Longmont's  'Cow Pasture Ocean'.  We picked up a bit of seaweed on that part of the voyage, but, as I remember it, when I finally was allowed some 'tiller time', I rapidly found the breeze and we swiftly shed that extra weight and drag.  She was a regular thorough bred after that!  Seriously, Gary she is a fine sailing vessel and I am genuinely proud to sail with you anytime.

    It's easy to tie sailing to ordnance.  Take a look at the deep sea sounding apparatus invented by Lt. John M. Brooke in 1856, below.  He used it to chart a route for an undersea cable from Hawaii to Japan in 1858.  Looks like it was fletching stabilized and had a core sample device as an integral part.  My soundings of Union Reservoir were accomplished with a very similar device. 

Tracy


Lt. Brooke's US Navy Sounding Device used for Pacific Ocean exploration from Wikipedia.

[seacoastartillery]

       All of these pieces of White Oak were cut for the 7” Brooke Rifle Platform.  Made from properly seasoned, air dried and kiln dried Pennsylvanian wood,  they are milled to precise dimensional tolerances which are +/- .005”on all thicknesses.  White Oak is extremely difficult to dry effectively, so you have to have plenty of references who can vouch for the competence of the lumber mill.  We have $900 of scrap wood in the basement from one wood buying adventure. We now buy all our white oak from one very small mill in Pennsylvania who supplies us and two other customers each year.  They air dry for 6 months and kiln dry for 6 months which works up to squares which are 3.25” X3.25” X 30” long.

     The core of our platform is made of a solid plug of Baltic Birch plywood 22” Dia. X 2.10” thick.  A smaller, 7.50” Dia. Baltic Birch column supports the top of the Pintle-Plate Pedestal.  The original platforms and pedestals used heavy baulks of solid oak or yellow pine timbers.  Turned steel or wrought iron Pintle-Pins and Plates were used. Sometimes Pintle-Pins went 3 feet into the earth beneath the platform.  Well seasoned timbers were in demand for the top of the platforms so as to keep the Traverse Track as flat as possible.

     We sure hope you enjoyed seeing what was under the surface lumber of these seacoast platforms.

Tracy and Mike

                                                                       Parts Key

1     Platform Radial Support   The original support beams were 12” X  12”.  Ours are 2” X  2”.

2     Deck Plank large                 The original planks were 3” thick and 12” wide.  Ours .50” X  2.0”

3     Deck Plank medium

4     Deck Plank small

5     Deck Radial Support Beam

6     Large  Pintle-Plate Pedestal Planks    The original Pedestal was Octagonal shaped and a little more than 7” thick and a bit more than  51” across the flats.  Ours is 8.55” across and 1.20” thick.

7     Small Pedestal Planks

8     Pintle-Plate mock-up with integral Pintle-Pin    Mike made this quickly from scrap aluminum to allow us to see how everything will appear when assembled.  Only Iron, steel, brass and white oak will be used in the 7” Brooke re-creation, all authentic materials.

9    9     Traverse Track Support Beam    Eight of these beams form an octagon shape which supports the Traverse Track  upon which the four  Chassis Wheels roll.   
   

The platform being mocked-up and dry-fitted.  These are rough cut white oak pieces.  No angles or final lengths have been cut.





The rough-cut wood for 4 Platforms.  Even with only about 10% waste, this is all you get for 35 board feet of lumber!     

    

[seacoastartillery]

     As we are both working on the platforms now, Mike and I thought it might be a good time to show the last bit of metal work to be done until the Montana shoot is over.  We recently performed a muzzle cut-off operation and a cascabel end shaping and cut-off op.  These are fairly mundane machining ops, but because the parting tool can get jammed as the cut-off pc. breaks free, this operation deserves a close look, especially for all you new machinists in this group.

     Per the usual routine, the explanation is available via the captions.

Mike and Tracy


This is mostly bull-work, horsing the 105 Lb. Brooke tube up to the lathe one more time.  Yes, Mike does have the heavy end, but he is the youngster in our team and my job is mainly to steer the beast toward the center of the 3-jaw chuck and watch all the piece to avoid dent causing collisions.




Mike places the wooden stop block into the 3-jaw to keep the tube from riding forward, pressing against the chuck's jaws and screwing up the cascabel radius which is complete and polished.




Visible here is the muzzle to be cut off, the open steady rest and the steady rest bearing ring with it's tapered I.D. applied to the tube just 1" from the parting tool cut.




Wooden blocks for placing the tube into position and protecting the lathe's ways and the little one in the 3-jaw.




The parting tool begins to cut at low RPM, about 80 with plenty of high-sulfur cutting oil.  The steady rest is closed and locked to support the tube when the muzzle center is cut off and the tailstock center no longer can support the tube's weight.




The blade can be seen here cutting the dark groove into the tube.  Parting tools are rectangular in shape at the tip and have minimal tool rake or top surface angle.  The relief angle is critical for it must allow for clearance between the tool and the material not yet cut, but it must be minimal in this respect, because there is terrific pressure exerted on the cutting edge of the tool because of it's broad contact with the revolving work piece and the tool needs all the support it can get!





Just before the muzzle end piece falls off and it just begins to quiver a little bit, we back off on the tailstock center pressure completely to AVOID JAMMING the parting tool between the new muzzle end face and the cut-off piece.




In our experience when the cut-off op goes well, the parting tool makes those tight little curl type chips seen here.
Not shown is the 45 deg. crown op which comes next and stoning the muzzle face to remove burrs and polish it.




Next we swap ends for a casabel end shaping op.  Mike has his spherical radius number sheet under the hack saw.  A std. left hand turning tool is used.  Tip radius is 1/32".




No, your eyes are not deceiving you, the end of the cascabel has been already cut-off.  Mike is so darn quick I have to check on him every 10 minutes or I miss the shot as happened here.  We put 'er together again for this pic, something the King's Men could not do for Humpty Dumpty!




With the cut-off piece removed you can see the large spherical radius Mike cut and the nub still left.  This nub will be removed in a subsequent op which mills a 1" high, square groove, horizontally across the entire cascabel surface.  This groove receives the Breech Strap which holds the Trunnion Ring onto the tube.




That hole also disappears with the 3/8" deep X 1" high grooving op.

[1Southpaw]

Are you saying you don't power feed the cut off tool ?   
 
I know a guy that tore up his lathe doing that . Then his friend posted pictures to the internet to show what lunitcy his friend practices 

[seacoastartillery]

    Ernie, Power Feed?  Us??  Never have tried that.  The only thing that will make more unusual, read that as  SCAREY and DANGEROUS  noises, is turning a small dia. rod at high RPM with 3 or 4 feet of unsupported rod to the left of the headstock!

     The unsupported rod quickly bends at 90 degrees as the lathe winds up, and then The Fun Starts!  Plastic tool cabinets are destroyed by the rotating steel whip and all those nicely sharpened tool bits go up to the ceiling like a canister charge, breaking ceiling tiles and large flourescent bulbs, adding broken glass to the number of missiles in flight.  It takes a moment to realize that you screwed up badly, but because horrifying events are always in slow-mo, you have plenty of time to shield your face as you dive for the emergency shut-off/brake!

Tracy

[Frank46]

Mike and Tracy, beautiful work. I had the pleasure of watching a 3' piece of 1/4" brazing rod do exactly what you described. turned 90 degrees and began to flail anything within reach. Was and I freely admit to be the cause of all the excitement as I was trying to drill and tap one end to make a cleaning rod for a friend. been there, done that and don't want to repeat that again. Frank

[seacoastartillery]

     Thanks Frank.  I guess the noise factor of my machine shop incident made it's details most vivid in my memory.  The cacophony of discordant sounds reached a crescendo as sheet rock was thrashed into powder, cinder blocks scored, plastic storage containers splintered and tool bits ricocheted off the ceiling and back wall and the glass from 4 trouffer tubes went everywhere.

     Since the tubes are very nearly complete now,  we are now concentrating on the Platform, both wood and metal.  We divide the Platform into two basic sub-assemblies, the Base which supports the Traverse Circle Track segments and the Pedestal which supports the Pintle Pin and Plate.  Items to create are the Deck which surrounds the Pedestal and the Pedestal, itself.  Making all the metal parts and hardware comes next.
 
     First the radial supporting beam recesses must be milled, a finicky and meticulous job.  Photos of this process were taken yesterday and will be shared later today.

Almost forgot, how would you make a Traverse Circle Track, 1/4" thick X 3/4" wide X 24" O.D.  There are 4 equal sections.  The horizontal surfaces have to be flat and parallel.  Low carbon steel is chosen because it's properties are closest to iron. 

Tracy

[Cat Whisperer]

...

Almost forgot, how would you make a Traverse Circle Track, 1/4" thick X 3/4" wide X 24" O.D.  There are 4 equal sections.  The horizontal surfaces have to be flat and parallel.  Low carbon steel is chosen because it's properties are closest to iron. 

Tracy

Industrial strength HO gauge.

I see another gee-whiz fixture in the future ....

[shred]

Model train track is available in a lot of small-to-middling sizes.  Above O-gauge, everything is sold as separate rails & ties, so you don't even have to destroy a section of snap-track . but you aren't likely to turn it up at Hobby Lobby...

[GGaskill]

Almost forgot, how would you make a Traverse Circle Track, 1/4" thick X 3/4" wide X 24" O.D.  There are 4 equal sections.

Is the track 1/4" high or 3/4" high?

[seacoastartillery]

    This confusion is entirely our fault, fellows.  I posted the photo that inspired us to start research on the 7" Brooke Rifle about 3 years ago.  It should clear up any lack of understanding as to which way the iron Traverse Track should lie.

    The track , at 1/6 scale is 1/4" high, 3/4" wide and 24.35" O.D. and 22.850" I.D.

Tracy and Mike are having a tough time deciding on how to make these 4 track sections and we are not afraid to ask for some help. Please keep your answers inside the box of standard machine shop practice.  Thanks.  We must be able to sand the top surface with traditional sanding blocks.  We DO NOT have a Timesaver.  Thank you.

M&T

The 'Ironclad Killer' in 1863-1865 at Battery Marion, 200 yards down the beach, west of Fort Moultrie on Sullivan's Island in the Charleston, South Carolina defenses.  Image from loc.gov. Photographer unknown.  Three larger versions are on there; I have not the slightest idea how to transfer them here.

[GGaskill]

We must be able to sand the top surface with traditional sanding blocks.

The track is wood or steel?  Thought it was steel.  If it is wood, you should be able to cut it with a router on a radius bar.  Glue up a hollow octagon big enough to contain the end product to start with, then soak four joints loose to get four quadrants.

If it is steel, flame cut an oversize ring.  Then, how about a sacrificial table on the rotary table and cut it on a milling machine?  Then saw into four pieces.  If it were my rotary table, it would have to be blocked up to clear the crank handle so maybe you wouldn't need the sacrificial part.

[seacoastartillery]

      The track sections are to be low carbon steel.  Thanks for your response, George.  Our main problem here is the unavailability of cold rolled steel in 1/4" thk. plates.  According to Mike who called a whole bunch of local steel suppliers, cold rolled is available in 1/4" X 2.0" bars at the widest.  We need 20 inch width to get a quarter section out of a plate on the bandsaw or mill.  Hot rolled in all sizes is available, but Mike will not mill that to shape; he says it burns up end mills and cannot be sanded, (polished).  As he sees it, the choice is to slip-roll cold rolled .25" x  .75" bar stock or to bandsaw hot rolled plate and then grind the edges to a scribed line on the 12" disk grinder and the 3" dia. reciprocating spindle sander for the I.D.  Pickling after shaping to remove the 'furnace finish' follows this; only then can the top surface of the sections be sanded with wet and dry paper to get the required 240 grit surface finish.  Does anyone have a problem with one or both of these methods?

Tracy and Mike

[GGaskill]

Well, how about the octagon from 1/4 x 2 cold rolled?  It would just fit.  TIG the permanent joints and tack the temp ones.  Band saw the excess, sand the outside to shape.  Inside will be more of a problem but not insurmountable.  Might have to do some flattening after welding.

[1Southpaw]

Friend has a cnc plasma table . Would be a piece of cake to cut 4 quadrents to your dimensions . He had lots of 1/4 " steel left over from the oil tank building days ,  The corners of the steel from a round circle are rems  that some one else paid for . Check out
www.mtmaverick.com
 
He could probably have it for you when you come to the CB shoot .
Ornery old fart  but can be worked with .

[Double D]

Ornery old fart  but can be worked with .

He is not not!!! He is a former  Marine Office is all!  Semper fi, do or die, drop and give me 50 and 100 more for the Corps....

[Double D]

      As he sees it, the choice is to slip-roll cold rolled .25" x  .75" bar stock or to bandsaw hot rolled plate and then grind the edges to a scribed line on the 12" disk grinder and the 3" dia. reciprocating spindle sander for the I.D. 

Tracy and Mike

Hoop bender.  Kind of like  tube bender.  Shop in Redding CA that made the rims for my Parrot wheels had one and was making stacks of flat tracks for some sort project for a sawmill.  Big heavy arm that rotated in a circle.  Don't know the details how it worked  but is was fast and pulled the metal through the jaws.

[dominick]

M & T, 
I'll just throw some ideas out there how I did some of these hoop shapes in the past. The track hoop you need to make sounds similar to the D shaped base ring I need to make for the naval Hotchkiss mount, only with a larger diameter.  The best [most efficient] method is to have them water-jet cut.  The process removes the mill scale and leaves a smooth finish.  The other method I used for curving flat on edge is to clamp it "edge up" to a 1/4" plate ring fixture [with guide tabs on each side of the plate] and pull it around the plate.  This would be tough with cold roll as it would have some spring back.  Heating the CR flat bar would allow it to follow the fixture more closely. Hot roll bends easy and would follow the jig with very little or no spring back [with heat].  I guess you would only need to make about 120 degree pieces and cut to 90 degrees with this method since it is a four section track.   
 Dom
 
Additional note:  A bender arm with a roller can be made to roll the pieces around the plate.

[seacoastartillery]

     Thank you to all who contributed your ideas.  Bruce brought a tube bender over so we could study it.  Such a device would have to be heavily modified to bend our track pieces on edge.  Without robust guides, the steel, mounted 'on edge' would flop over and that would be the end of that method.  Welding is out per Mike who has had several "experiences' with welds that look good until you blue the parts then, yuk.  I layed it out and technically it would work just fine. Thanks George.  I guess I will defer to the man who will be doing the work.  Mike decided that he is willing to put up with the vinegar descaling op, ( Thanks Double D.), and we will go with hot rolled plate.  We will get new 1/4" plate from our favorite surplus yard and save about half the cost of new from the steel distributor.  We will pay 70 cents per pound.  $55.00 will buy enough steel to make track sets for all four Brooke Rifles.

     Dominick's water-jet method sounds really good, but the cost is a bit steep for just a few parts, we found.  Mike says we can cut the curved track sections on our metal working circle cutting fixture made from Baltic Birch plywood and a 3/8" hardened steel dowel.  He will the finish the edges on the disk sander and the reciprocating spindle sander with a 3" dia. sleeve.  3 days of pickling in white vinegar will descale the segments and then top surface polishing can be accomplished.

Tracy and Mike

Now back to wood working:  I am building the platform which supports the Traverse Circle Track we have been discussing.  We have yet to build the Deck and the Pedestal.  The Pedestal core is very important as it takes a lot of abuse during recoil of the gun.  We make the core out of Baltic Birch for strength and dimensional stability.  White oak covers this plywood and is strong, authentic, and good looking.  Here the 7.5" dia. cores are slathered heavily with yellow glue and clamped.  A 1" dia. oak dowel keeps the disks aligned during clamping.




With the Platform upside down on the mill, we prepare to cut the notches for the white oak Radial Support Beams which tie the white oak octagon track support to the massive 22" dia., glued-up, Baltic Birch Platform core which is composed of 3 full thickness, plywood disks bonded securely together as one.  This plywood monolith prevents our Brooke Gun Platform from warping if it is delivered to a high humidity state like Alabama as one of the 4 will be.




Here we use an adjustable parallel bar to check the width of the notch.




The parallel bar is measured and it looks like one more pass should do it.




Well it took 3 passes to get the width out to 1.998" which is 3 more thousanths than the beam end which is 1.995".




All notches are complete except one, then the octagon shaped white oak is cut off on the bandsaw circle cutting fixture, then the circular base is sanded upon the same fixture on the 12" disk sander. 

[GGaskill]

Welding is out per Mike who has had several "experiences' with welds that look good until you blue the parts then, yuk.

You do have to match the chemistry to eliminate bluing issues but the easiest way to do that in this case, where the weld would be in a very low stress environment, would be to cut some narrow strips from the material to be welded and use that as the filler metal.

[seacoastartillery]

    George, thanks for the welding tip.  This time we have bandsawed a hot-rolled plate to make the Traverse Track segments.        We are making steady progress on the 7" Brooke and the past few days have seen the cutting of the Traverse Tracks for mounting on the platform.  Then the track sections were pickled in 4 gallons of white vinegar and removed 3 days later completely scale-free per DD's idea.  All the remaining deck planks were cut and then cut at a 22.5 deg. angle on both ends to fit the concentric ring octagon pattern.  The deck supports were secured to the platform baltic birch core with deck screws AND glue for maximum strength.  The bathtub areas between the radial deck supports were painted with an oil-base gloss black enamel paint to simulate a water drainage area covered with tar to channel rainwater to a central drain and then to a subterranean sump filled with crushed rock and sand.  No muddy boots for these heavy artillerymen!

 Tracy


The 1/4" thk. plate, 20" X 48" waits to have the last cut for the fourth traverse circle track.  The steel is not shifted during the cutting on one track segment.  The whole table with the pivot pin and the steel plate on it are moved via a spacer block added or taken away depending on which cut you want to make, the outer or inner radius.








Here is the circle cutting fixture in the 'back' position without the spacer between the fixture's back edge and the stop  stick being held by two smaller c-clamps.  The last cut for that particular pivot pin position is about to take place, completing the fourth track segment.







A view from the other side shows the way we get the circle cutting fixture back into position for the next cut.  The combination square re-locates the fixture's corner each time the spacer is removed or added.  The start point of the "other" bandsaw blade position can be seen along the blade slot in the fixture board. 







This shot shows the eight pivot pin holes in the low-carbon plate.  We get eight track segments to the left of the holes and also eight to the right, enough for 4 gun platforms.





The pintle core and the radial deck plank supports have been screwed down after liberal use of yellow wood glue was applied.  All screws will be permanently covered by the oak deck planks. 


Black enamel paint is applied to 'wet areas' of the platform.




The planks go on next and the oak pedestal top plate covers the edges of the deck planks and covers about 1/2" out from the baltic birch pedestal core.

[seacoastartillery]

     Some photos of recent work are posted below.  Unfortunately there is no time to make iron sights for the Brooke.  We will bring our "drill no holes" scope mount and the 'ole Weaver' along for sighting. The wood and the metal will have finish and bluing done after the shoot.  This gun is much larger and heavier than the 100Pdr. Parrott.  The platform alone weighs 38 Lbs., the tube 100 and the upper and lower carriages 35 Lbs. together.

Tracy and Mike


P.S.  When the photo hosting site completes their maintenance, we will re-post the pics.Shop layout for 'deck plank' fitting.  The disk sander is excellent for free-hand angle sanding, but it's a long run to the dust collector.The gap fixture contains two drill bits and super glue holds the parts temporarily until we have time to drive the dowels or spikes in.Mike grinds the steel of the traverse circles down to the scribe line.Marking the track segment number on the platform.Marking the traverse circle segment.The last segment is placed over 4 hold-down studs epoxied into the white oak of the platform.  Uniquely slotted, round, countersunk nuts are slightly less than flush with the track's surface. .[/color]

[seacoastartillery]

Finally, the photos have arrived.  T&M


Shop layout for 'deck plank' fitting.  The disk sander is excellent for free-hand angle sanding, but it's a long run to the dust collector.




The gap fixture contains two drill bits and super glue holds the parts temporarily until we have time to drive the dowels or spikes in.




Mike grinds the steel of the traverse circles down to the scribe line.




Marking the track segment number on the platform.




Marking the traverse circle segment. 





The last segment is placed over 4 hold-down studs epoxied into the white oak of the platform.



Uniquely slotted, round, countersunk nuts are slightly less than flush with the track's surface.

[flagman1776]

delete

[seacoastartillery]

     Thanks for the tip on realistic train tracks being available. This info will probably come in handy on our next gun, the big 150 Pdr. seacoast rifle by Armstrong, a British import to the Confederacy in 1864.  It's carriage, mounted on the seawall of Fort Fisher, was supported by railroad style I-beams bolted to a timber platform.  As you can see in reply #26, this brooke rifle uses flat, relatively thin iron traverse circle track segments for 360 deg. of traverse.

A few more 7" Brooke construction pics are below.

Tracy


We made round, countersunk, slotted steel nuts and a special wrench to drive them just like the original hardware.




This is our first use of the plate joiner on this project.  This versatile machine cut short arc-shaped slots into which pressed, wood-product, 'bisquites' are placed with woodworker's glue instead of dowels.  We are making the five piece, white oak Pedestal which tops the platform as far as wood is concerned.  There are 4 slots per side on each piece.




The fixture in the center took all of five minutes to make, yet it holds two pieces in position for slotting.  You slot, release, flip 180, and slot again.  4 minutes for 4 slots.  The pieces change place and repeat previous steps for the last 4 slots.




The five pieces are glued up, bisquite connected and clamped for a flat, tight, no gap, assy.




Pedestal top and track mounted on platform.  Assembly will be done on Monday and the Pintle Pin/Plate will be attached with four robust, scale bolts and the Pedestal top is bolted down securely with eight sturdy bolts to help the Pintle Plate and Pin resist movement during recoil.  Then we will the mount the Chassis on the traverse track and the Upper Carraige on the Chassis and the Tube on the Upper Carriage.  Then you fellows will finally see what we will be shooting in Montana.

[seacoastartillery]

     This gives you an idea of what we have been building and what will be shot in Montana.  No we didn't have time to apply a coat of finish to the white oak of the Platform.  When we proofed this gun it sent a 9 oz. bolt into a 60lb. chunk of boiler plate an inch thick.  Our bolt stayed in the plate, but it knocked a 5 oz., oval shaped piece of boiler plate out the backside!  This thing has power and strength to spare.

Tracy

7" Treble-Banded Brooke Seacoast and Navy Rifle M1862