Titanic Hull

[David Haisman]

Well done you two,

I reckon we could build our own ship after all this info and perhaps call it '' E. T.''

All the best,

David H

 

[david wilson]

regarding robert hauser's question "how are the plates joined at the butts in each strake?"well robert here goes!.titanic,as we all know was in & out straked.an inside strake was knuckled(bent) outboard at the aft end,on a machine called a butt breaker,for one thickness of plate.that is to say bent untill the inside edge lined up with the outside edge projected aft.the fwd butt was knuckled inboard like ways.the knuckle at the aft end was then scarfed{planed flat)in way of the horizontal seam lap.the fwd end wasn't touched.the outside strake was knuckled outboard at the aft end & inboard at the fwd end.the knuckle at the fwd end was scarfed in way of the horizontal seam lap.if one was to look at a butt in plan view(looking down)you will find that there is plate alignment all the way around the boat,just like a carvel or clincher boat were the planks have been scarve joined.
shipbuilding in the olympic's day was very labour intensive.for example,to produce a shell plate in the area where a boat has twist ie towards the stern or bow,there is 11 or 12 operations.
1)template lifting.
2)marking.
3)punching.
4)shearing.
5)planing.
6)countersinging.
7)butt breaking.
8)scarfing.
9)rolling.to frm set & twist.
10)delivery to slip
11)red lead in way of frms,butts & seams
12)erection & screwing up.
13)reaming every hole.(drillers)
14)rivetting.
if anybody is interested in each of the operations above in detail,i will be glad to.
i am also prepared to describe the method of bending & setting a furnaced frame.
i hope this helps you robert!.
regards.
dw

 

[Michael H. Standart]

David, I think you'll find quite a few of the tchies here that are more then interested in this. In fact, you might even want to pen a series of posts about these techniques or even an article for publication here on ET.

 

[Scott R. Andrews]

Hello David,

Thank you for your very interesting post. What you said about the scarfing of the corners on the inside and outside strakes was exactly the point I was trying to get across in my above reply to Robert, but you stated it much more clearly than I did!

As for whether anyone would be interested in hearing about bending and setting furnaced plates and frames, I couldn't agree with Mike more. While there are quite a few here with general knowledge of what was involved in riveted ship construction, there's a lot that we could all learn from someone with practical experience like yourself. The fact that you practiced your craft at H&W certainly makes it all the more interesting!

One question I have regards the application of knuckling at H&W. Did they do this with steel of all thicknesses, or was it limited to any particular minimum thickness and greater? The reason I ask is that the practice with some builders when dealing with butt laps in thin material, such as in the superstructure, was to pull the butt lap tight with bolts during hanging up. I was wondering if you knew whether H&W did this at all, or if they machine-knuckled the lighter steel as well.

Thanks again,
Scott Andrews

 

[Noel F. Jones]

"Back to the butt joints for a final note. On Titanic they were arranged so that any vertical edges faced aft. This was thought to provide a "smoother" surface. Only later with the development of aerodynamics was it discovered that this method actually created "burbles" in the water flowing past the hull. These burbles rrobbed speed and increased fuel consumption. It was learned that butt seams should be reversed. Unfortunately, by then welding had become the way of shipbuilding."

I recall reading somewhere that the seam overlaps in the Bremen (and presumably Europa) were indeed aspected forward. It was found that the resulting eddy-making resistance was a lesser penalty that the thus-displaced frictional resistance.

Noel

 

[Andrew Fanner]

Were rivet holes all reamed? ISTR reading that not reaming rivet holes was an issue at one time, the process of punching holes to size leaving microcracks in the surrounding structure that could, and did, propagate leading to localised failure.

Please post more, it was very interesting.

 

[Scott R. Andrews]

Andrew,

That's a question that I can answer. Before most ship classification societies made it a requirement, punching holes to size was common practice. By the time the Queen Mary was on the ways, reaming to finished size was required. Before then, reaming of holes was mostly employed in correcting serious misalignments.

This is not to say that before the late 1920's shipbuilders didn't know about or appreciate the problem of microfractures associated with punching holes; they were well aware of the potential problems. They also had a much better appreciation of just where in the vessel they could safely (for the most part) employ punched holes and where they needed to drill holes or ream punched holes to finished size than most people this side of the 20th century give them credit for. When looking at the structural drawings for the Olympic and Titanic, there are several instances in high-stress areas where drilling or a secondary reaming operation is specified, as well as some fairly large expanses where steel rather than wrought iron rivets were specified.

Regards,
Scott Andrews

 

[david wilson]

Hi,guys,I posted an article on template lifting of a shell plt last evening.I'm wondering how long before it appears here!Can anybody answer asap,please.
regards.
dw.

 

[david wilson]

Guys,I'm here again.I don't know what happened to my posting last evening on lifting a template of a twisted shell plt.Here we go again.I'm not much of a computer buff,because they have destroyed my trade,se la vie!.Don't drink red wine when using one of these contraptions!especially Western Australian cab sav!!!.
The plating dep't in H&W was divided into various squads:-shell,frame,deck,beam & bulkhead,
these were known as the "big squads"nobody was paid more than these guys.These squads evolved from the ould timber boatbuilding days when squads roamed the country plying their expertise,there was no overlap.The other squads were some what smaller,4 men & less & the wages reflected this.All the way down to todd sloan,who was paid the least.There was a saying in east belfast,mother giving marriage advice to her daughter "if you can't marry royalty,marry a big squad plater".The big squads were themselves divided.For example,the shell squad(hull)had a template lifter,markers off.punch&shear man,rolling man,furnaceman & hangerup.Everybody was on piecework,you only got paid for what you did,not how long you were there for.There was a limited amount of overlap within each squad but mainly template lifter,markers off & rollers done nothing else except their designated tasks.The squad leader(not a foreman in himself)dictated what the rest of the squad's allocated tasks were.There was no quality control as such,everyman took pride in what he did.Every boy that went through H&W was brainwashed into believing that he served his time with the biggest & best shipbuilders in the world.
The template lifter,his helper & probably a boy armed themselves with 2lb hammers,3/4"tacks,
a few dozen clips(similiar to old fashioned push on clothes pegs,made from 1/2"round bar flattened at the ends & turned out.From the store,100'of batten,3",4" & 6"wide(batten was 3/16"thick oregon pine(douglas fir).The most flexible & durable boatbuilding timber I know!.I must explain.The mouldloft produced,in template the keel plts with holes drilled,buttlaps & seamlaps marked,with countersinking & scarfing.This was "A" strake.The strake either side was missed,this was "B"strake (or garboard port & starboard).The shell squad lifted the rest.The 6"batten was pegged onto the seamlaps first,then the buttlaps.Battens were then pegged onto all the frms encompassed by the template.Diagonals were tacked on to comply with Euclid's second law of triangulation!!!.When lifting a template of a plate were there is frm set & twist(twist occurred getting away from midships towards the bow & stern) packers were inserted between the fayside of the template & the butts,seams & frms to ensure that the fayside of the template represented the mean of the plate to be fitted.For example,titanic had, I believe, 1" plt.The packers for the "in" strakes would be 1/2" & for the "out"strakes 11/2"Everybody then armed themselves with a sharp pencil & marked every hole in the butts ,seams & frms.The boat#,top,fwd,plt#,strake letter(plts had a# strakes had a letter)port or starboard.All of this was written at the fwd,top inboard side of every plt.Tradition.If one was to walk round the inside of a H&W boat,all the shell plts identity were in the same place.This helped the hanger up were to put his shackles,for obvious reasons.
This next bit is difficult to explain.It's to do with finding the rolling line.That's the line on the plt which is kept parallel to the axis of the rolls.If we were doing this together it would be simple to show you.Here goes!
We go to the first frm covered by our template.We use a piece of our batten which reaches the existing plts,mark the centre of the batten.Our boy holds this batten in such a way that the centre mark is approx mid space & at a tangent to the frm(are you still with me?).We now go to the last frm covered by our template & with another piece of batten, similiar to the other,we line sight the top edge of this batten to the top edge of other & touching edge of frm.When both battens are aligned this is marked on our template
& a chalk line struck between them.This is our roll line & is marked on the plts port & starboard
The template is moved to the corresponding place on the otherside of the boat & things are reapeated.Template is handed over to marker off.
This will be our next task.
To be continued.
regards.
dw.

 

[david wilson]

Hi scott,
to answer your question about knuckling & joggling.H&W could knuckle plate up 11/2"& joggle up to about 1/2".In all my time there I never seen a plate wheel joggler,but I did use the dk beam joggler on rare occasions.You have to remember that rivetting was on the way out.H&W were welding dk butts & rivetting the seams.The shell plating might have gone the same way,this eliminated the need to knuckle the butts to accomodate the seam laps.I think the main reason for this was the probable lack of qualified arc welders,but there was a glut of rivetters,holder ups,heater boys & catch boys!.During WW2 I believe was the instigation of dillution labour.This is a situation were the company has plenty of workers,but not the trades they require.So the answer was to train the rivetters to weld.Hence the two week wonders!Two weeks in the welding school & get on with it.The condition was,with the unions,come layoffs these guys were the first to go.
Sorry I can't help you anymore on the joggling.
regards.
dw.

 

[david wilson]

Andrew,
I am posting a series of articles in the near future on the stages a rivetted,twisted shell plt has to go through,right up to erection on the boat.You will be able to form your own opinion on whether or not these holes needed reamed !.From pencilling the holes onto the template,wood punching the estimated centre of the pencil mark onto the plt,putting a ring of white paint around this dab mark with a piece of copper or brass pipe, same dia as the hole then punching the holes on a "one man punching machine".They did not have the benefit of a punch with a centralising pointer on the face of the punch like today,they had to get inside the white paint.The plater would be sitting down & the punch would be at his feet.This punch,as all punch & shears then, worked @ a rate of 28 strokes to the minute & the plater "ran them" that's to say ,the punch was always "live".
Say our plt is 25'long x 8'wide,that will cover 10 frm spaces @ 30" each=300". 8' wide will cover approx 32 holes on each frm,that makes a total of 320 holes in the frms only.The seams top & btm will account for another 400.The butts another 128 for a grand total of 848 holes approx per plt.I am aware that the seams & butts double up,but this still makes 848 holes you have to fill with a rivet.Considering the method of marking & punching do you honestly think all of these holes will be clear holes ready to accept a rivet?.I don't think so & that was why ALL holes were reamed.
I trust this helps you.
regards.
dw.

 

[david wilson]

Hi,Michael.Regarding the strength of titanic's steel!.I witnessed an incident at H&W in the early seventies that put me off ever working on a steel boat ever again.H&W were building an O B O(oil bulk ore) boat on a slipway,in their east yrd.A weldment(prefab)was due to arrive from the victoria works fab shop.When a multiwheel arrived to transport it,somebody noticed that the erection lifting lugs were not fitted.The weldment was a bilge section,complete with shell.The foreman marked the shell with two x's & told the tradesman to fit two x fifty ton lifting lugs,as the section weighed 60t.The tradesman took him at his word & fitted the lugs on the x's.He should've aligned them with the internals,but didn't.Weldment duely arrives at slipway,but because of the delay it was now go home time & the load was left on the ground in it's approx position.That weldment lay there all night in sub zero temp!The next morning the boys hooked her up to two 40t cranes.Ten foot in the air & one of the lugs pulled a piece of shell out about the size of a standard dartboard.The shell was 11/2"plt.I can still see that rupture,there seemed to be like spangles in the plt,like a glistening,similar to a piece of coke.
Is there a metalurgist out there who can explain to me in layman's terms what caused that to happen?.
In the winter time,we always kept our lifting gear around the fire,I would like to know what effect the severe cold has on mild steel.
regards.
dw.

 

[Andrew Fanner]

Severe cold brings about the infamous ductile/brittle transition temperature, the bane of many a Liberty Ship as it was taught me at Uni years ago. There are contributors far more qualified to explain this than I am but in essence below a certain temperature some varieties of mild steel stop bending under stress and crack instead. It become even more important to avoid stress concentrations such as sharp corners if your construction is to be exposed to temperatures below about 4 degrees Celsius for extended periods. The North Atlantic is a good place to do this, as is a Belfast shipyard in winter, or indeed my home workshop on Saturday when the heating failed:-(

 

[david wilson]

Hi everybody,to continue the saga of the rivetted,twisted shell plt.The marker off in the shell squad was provided with a drawing called "the shell expansion".That is to say,a drawing about 10'long, depicting,butts,seams,frames bulkheads & off course the shell plating.Only half of the shell was shown,plus the keel plt.This drawing was only diagramatical,the only measurements on it would be the frm spacing,which was 30"heel to heel.The reason I say heel to heel is that the two frms that stradle midships face each other bosom to bosom.The forward frm the heel looks forward & the after frm the heel looks aft.The reason being,when we get into the area were we are beginning to turn towards the bow & stern,the part of the frm that carries the shell,the flange, will be open bevelled.This is to allow access for our rivets.If the frm squad frm setter didn't "open" each frm flange at the furnace to suit the relevant shell strake we would be up the proverbial creek.If the bevel was "shut"we couldn't get our rivets through for about 3/4 of the boat!
The main function of the shell expansion drg,was for identification of the plts & as a log to show what plts had went through.The board of trade insisted that NO butts shall fall in the same frm space unless there is at least three full strakes between them.This drg showed the butts.
The shell marker off always marked plts in pairs,port & starboard.Nobody ever said starboard & port.He clamped his template to the plts using the large clothes pegs.Himself,his helper & the app would then transfer all the pencilled holes & other marks & info onto the plts.Template would be discarded & would more than likely end up as fire lighters in some east end house.All the holes,which were marked with a wood punch,would be circled using a very short piece of brass or copper pipe to the diameter of the hole.
The plts would then be stacked on top of each other,ensuring that either broken pieces of batten,or punchings(blaes)would be spread out convienently,to prevent the top plt from smudging the paint on the btm plt.All very techno!!.
The next part of the operation,is punching.
This was carried out on a "one-man punch".This machine was ingenious in its simplicity.It was made up with a series of wheels,12"dia,on axles with sprockets & these would be united with bicycle chains.The whole frame moved,say,east & west on small gauge rails & north & south on the 12"wheels.The plater sat in a little house above the plt,this was to eliminate distractions.He sat the plt on the top wheels as near as possible to sqr as he could.He had two hand wheels to control azimuth,so the straighter he set the plt the easier life would be.He could nearly do away with using the other wheel.A good plater could run these holes,28 to the min.When he had punched a pile of plts he would seconde four helpers & proceed to sheer the four edges.He left about 1/4"of green all the way around.
The plt would then go to the plane.
To be continued.
regards.
dw.

 

[david wilson]

To continue the saga.Two things I forgot to mention in the last post.While punching the rivet holes,the plater also punched through the scrap,every three feet,to within 3/8" from the shear line.This enabled the scrap to break at these points whilst shearing.Another point on the shearing.The shear blades where 24" long,they didn't"(leave each other for 3")and the cut was 12"long.The plater guided the plate & the helpers pushed it through,hard yakka!!.
Now we go to the plane.This device was specifically designed to plane shell plts.It consisted of screw & hydraulic rams ,which held the plt in place whilst the planer(platers helper)travelled along the edges in a little bogie,shaving metal off down to the centre dabs(pops for our u.s. cousins).Under no circumstances could a shell plt be cut to size using heat!.We now go to the countersinker.All holes marked as such by the marker received this treatment.That is to say ALL EXTREME OUTBOARD HOLES.So to whoever it was that said the heads had been knocked off the rivets in the collision area,please thing again.The rivets were knocked up on the outboard & there is no way this could have happened.Back to processing.After csking,we go to the butt breaker.We break the butt one thickness (I believe I have explained the operation in an earlier post,please refer).Now to scarfing.This machine worked on a recipricol motion,similar to a machinist's shaping machine.Across & down in degrees.
Over to the shell rolls.Again designed for one purpose only.The plt was entered with the roll line parallel to the top roll.I'd better explain the rolls.We have two rolls on the bottom & one roll on the top,this is standard for all rolls.Shell rolls are different in that they are not used to roll complete circles.The plater here has three helpers,who are well versed in their
actions.The plater lifted his frm sets from the same scrieve board as the frm setter.The rolls were in the same locality.The setting of the shell plt to it's relevant frm sets was more critical than the twist,this could be pulled into position with chain blocks.After red leading at the slip,the plt was hung up by the shell hanger,who inserted as much as was necessary bolts to hold it in position.The shipwrights took over at this point.They maintained frm spacing, half breadths & heights.The plt would be drifted into it's intended position & screwed up tight.
A drilling squad(two men) would ream all holes concerned to the required dia.
Next came the rivetting squad.This(in titanic's day consisted of two tradesmen,holder up,heater boy & catch boy.Could be two catch boys,depending where the heater boy's fire was in relation to the holder up.The heater boy threw the white hot(only at the tradesman's end)rivet to the catch boy,who in turn picked it up with a pair of purpose made tongs & inserted it in the hole,The holder up jammed a 16_20lbs short shaft hammer against the head & our two tradesmen began knocking up the rivet.Sometimes the rivet would be a fraction too long,so one of them trimmed it off with a chisel & continued to dolly it off.Can you imagine what a man's arms would be like after several years of this.He probably would have arms like popeye!!!.I wouldn't like him to grab me by the throat,that's for sure.Hard men all.Can you believe that an american shipyard rivetter,beat JACK DEMPSEY in an arm wrestling comp?. TRUE STORY.
After several plts were rivetted the caulkers could begin making the butts & seams watertight.I can't really comment on this,cause I never seen it done,except to say that they used a special tool to turn the edge of the outside strake into the inside strake,better ask a caulker,if you can find one.I hope to be going back to the town of my birth soon where I hope to find someone who will enlighten me.The favourite place for this type of conversation is the MORNING STAR BAR in pottinger's entry,off high st, in the city centre.See you all there!!!.
regards.
dw.