K5 (E) Leopold
    in Scale 1:35 by Trumpeter with machined barrel

    Building Report
    Fitting the Chassis
    The Carriage
    Generator-/ Ammunitoncontainer fitting

    Author Th. Schrecke  2004-2015
    updated 05.03.2015

Preliminary Remark

This is the English Version of the Making of.. Page that was already published. To give our modelling friends around the world the chance to understand how to handel the kit and the machined barrel by 48 Special Models it was translated.
We recommend to take a closer look to this page before starting building the model. Although we don't think we know all about modelmaking it may be helpful to know the "mistakes" others did!

Instead of the German Version this is a finished Version which will not be updated anymore. 

  The Kit
  • The machined Barrel
  • Diorama preparations
  • The Base
  • Diorama
  • Shelter
  • Building Report
  • Fitting the Chassis
  • The Carriage
  • Generator-/ Ammunitoncontainer fitting
  • Painting


    Building Report

    I was aware that building the Leopold wouldn't be done on a weekend when I saw the closed box. It might take a month I came across after opening the box. But this will not be enough I think although I work a professional 40 hours week.  For a hobby modeller this means fun along the whole wintertime.

    It makes extremly sense to study the assembly instruction before the start in this case. As said before it is a little book and excellent as a bedtime reading. Have a pencil at hand to check mistakes and add notes. You can see which in the troubleshoot list below.

    Fitting the Chassis

    Before starting modelling all depressions in the parts need to be checked and filled with putty or superglue. I use superglue and a little kicker most of the time, because it is quick and easy. Large surfaces or thin layers are treated with putty. After sanding all parts should be spraypainted with filler/primer and the basic paint. All frame parts are tank grey. 
    The steps in the instruction show some problems in order. For example the wheelmount should be installed right in the beginning, then the leaf springs etc..

    In my kit the chassis frames where a little out of shape. This leads to a curve in the middle of the chassis. When cementing the upper and lower chassis this needs to be compensated by pining the parts in position with superglue and fixing them until set.

    A real challange is mounting the leaf springs. I cemented them first to the axle housings and put them in place by sticking them to the wheels. This is the only way to do it, because the axles can't be put in place another way. Take care to put the far end springs in place first, because the inner ones need to be adjusted to them. Also the wheels should be completely painted and aged. 

    Like to be seen below, the wheels were adjusted by help of a gauge I track and the o-rings were fitted first on the outside than on the inside. Therfore the leaf spring blocks haven't to be cemented. In fact I didn't glue them at all (like the original ones). Also the leafsprings should not have contact with the distance screw above. The track was held by rubberbands to the chassis and then the wheel sets were adjusted. After that the o-rings have been glued on. I started at the far ends first and went to the middle. Are the far ends fixed the rest adjusts automaticaly.
    After setting the track was removed and the procedure was repeated on the inside. After that a little paint touch up on spots you can't reach afterwards is necessary first. Followed by installing the breaks. These should be put in place dry first, to adjust them. After all parts sit in place they can be spot cemented with thin superglue. Notice that the struts (G3) can be put in place only after the breakstruts are installed! The rubberpads for the container on the rear trolley are different for the straight track and the turntable track. For the turntable the parts J44 (no rubberpads) are needed!

    I did the clamps (A & B) shown in the plan bend from wire, from brass and not from the copperwire that came with the kit, because it is more sturdy.

    After most of the worksteps I touched the parts up with a brush and  sprayed them over a little to vanish the edges. After that putting on all the small parts followed as shown in the instruction. So many aeras are hard to be reached afterwards, ageing should appeare now in some occasions.

    Correcting depressions on 
    the upper chassis.
    This needs care, because the areas can't be reached afterwards but are still visible!
    Assembly of the lower chassis and the wheel fixtures.
    This is how the leaf springs are supposed to be assembled. So it is placed almost in the air, it is impossible to be positioned.
    The solution is to cement them to the wheelhousing.
    And to prime and paint them by help of a wooden stick.
    Important is to spraypaint all hard to reach places beforehand!
    Many of the edges and angles can be painted only now. Tank grey is the ultimat color for that, because it was the basic color on any gun, even the camouflaged ones. 
    Ejector sprues at its best. More of then didn't find place any more.
    All wheelsets where assembled, primed and painted iron first. After that a redish brown was sprayed lightly over, to simulate rust.
    Only the tread were left out!
    The wheel fixtures and the lower side of the chassis also were sprayed rusty, because it can't be reached afterwards.
    The wheelsets are put in place dry now! 
    And will be adjusted on the track then.
     Rubberbands tie down the frame
    to the track and fix it. 
    Then the o-rings are cemented on.
    This should be done from 
    the far ends to the middle.
    After that the breaks and all other parts 
    are installed.
    The final wheels design can be aged again now.
    The completed chassis 
    (the wooden grating  is still missing ).
    The buffers and couplers.
    Good to be seen is the paint job done.
    The Carriage

    The carriage was worked on parallel to other steps. This is not the usual way, but I got used to completeing as much sections as possible up to the next painting step. This way I collect the sections to paint them at once and then go ahead. This saves worktime, by not getting the airbrush ready all the time.

    When assembleing the carriage I started making the hydralic cylinders first.
    The mainstrut which controls the main cylinder is made from two parts (M7) which doesn't make any sense at all. Before getting lost in sanding and leveling out, I simply cut of the whole thing and replaced it by a 8mm aluminum tubeing. It was sanded at the cementing areas and glued in place with superglue. After that it was cut to lenght. The strut is straight now and runs smooth to the cylinder.

    The support struts C29 have holes on the inner sides, which result from production. These holes will almost not to be seen, but are a weakness in structure. I filled them with superglue and glas bubbles and sanded them down to size. So they vanished completely. The support struts also could be exchanged with brass, but that I skipped for myself.

    It is helpful to preassemble all sections of the carriage. This means also the supporting bulkheads inside the carriage. Again all the many depression holes need to be filled first! This is nuisance and time consuming. I built the bulkhead boxes beforehand and painted them.

    The four sidewalls of the carriage do have each three depression holes on the outside! They also have to be treated with superglue. It is helpful to check the surface by useing original photographs.  There are a lot of pictures of the Leopold in the internet. Some can be reached from our linkpage too.

    The sidewalls have been primed grey first and then painted with XF-64 tank grey. The assembly of the whole carriage is quite complex, because a lot of sections need to be integrated. It is importend to take care of all moveable parts, to keep them movable. Modellers who use the machined barrel by Schatton/48 Special Models should read the section
    The machined Barrel first!

    The barrel will be testfitted first and adjusted so that it can be cemented in place later simply. When useing the machined barrel additional ballast is needed in the lock and carriage!
    When the barrel mechanism works fine, it will be cemented to the inner sidewall, on one side only first. The whole section will be slipped to the slots, adjusted and cemented with thin superglue from the opposite side (in between the walls). It is helpful to testfit the whole carriage beforehand first. The sides of the carriage consist of a double wall construction, which has bulkhead walls for strength. For a to me unknown reason, Trumpeter missed to design a minimum amount of stuctural support here. I can't imagine that the carriage can be build without additional supporting bulkheads at all. It definitly needs them, if the machined barrel is used!  Conditional on the weight of the barrel the occuring forces at the cradle need to be transfered most even to the carriage, to prevent it from going out of shape.

    I started preparing all parts. The lift mechanism needs a scratch build construction, when the barrel will be movable or fixed in raised position. I decided to make the barrel movable and I am curious if it will work.

    The original lift mechanism works as follows:
    The toothbars are moved by a gear and an electric engine and determine the elevation of the barrel. The lower hydraulic cylinder connected to them equals the barrel weight by hydralic pressure. This way the barrel can be moved with a minimum of force. The parallel support struts transfere the forces to the barrel. To solve this without loss of force the mechanism is guided on a rail in the middle. This secures a direct transfering of forces. Underneath the barrel itself only a recoil break cylinder is mounted, which stops the barrel recoil. 

    On the model the principle works the same way, except for the mass compensation by the main hydralic cylinder. This one is without function, but moveable. To double his task another source of force is needed, i.e. a coil spring. The missing engine support is compensated by the scratch build guidance block, which takes care of parallel toothbar movement. To the end of the toothbars a coil spring is fixed, which is also fixed to the inside carriage end. Therefore the carriage wall needs  structural support. 

    The whole carriage box needs to be supported by additional bulkheads inbetween the outer and inner wall. Unfortunatly no data on the original where available on that item. So I had to improvise. In general it can be assumed that the vertical bulkheads at positioned at areas, where the dimensions change and cross bars are located at the lower side. So I put in 2mm thick and 12mm wide styrene sheets here. These were cemented inbetween the edges on the inner side of the sidewalls. The way the horizontal bulkheads were placed can be seen good on the pictures. So they don't show after assembly they are cemented about 1cm above the lower edge. This makes it a kind of a boxlike structure. On the top I cemented a strip of 1mm thick styrene along the whole edge.  This is necessary, because the second, outer sidewall can be finaly cemented in place only after the barrel mechanism is mounted. At the right, smooth side this already can happen when the bulkheads are installed. To prevent the carriage box from bending, it should be clamped to a even support, like an aluminum angle profil. This keeps it straight. Now it can be superglued. The left sidewall will be only put in place dry, to adjust the construction. It can be cemented in place after the barrel mechanism is installed completely!

    Now the changes on the lifting mechanism are made. Therefore two 5mm styrene sheet of 2x4,5cm are cut out and sanded parallel. They have to fit smooth inbetween the inner walls. On one sheet the centre axsis is marked and the exact distance of the guidence notches of the toothbars too. There will be two 1mm wide and 1,5-2mm deep slots cut out, in which a strip of 1mm styrene is cemented. It shouldn't be a much harder material, to prevent wear. These will be sanded down to 1mm of hight.  This can be managed easy by placeing inbetween a strip of 1mm thick styrene. Now only sanding to fit and the parallel guidance is ready. Now a distance block of 4,5mm needs to be placed inbetween the two plates. A centered hole on 3mm is drilled centered to the left and right side, to take a bolt from aluminum or brass wire. These guarantee a stable rest and the posiblity to adjust the angle, before cementing in. The guidance block is positioned direct in front of the second bulkhead and adjusted to its angle. To the inner sidewalls fitting 3mm holes are to be drilled too.

    Is it placed correctly the toothbars will walk through it smooth, prallel and straight in line with the hydralic cylinder. Also the toothbars don't leave the block and point out about 5-8mm. To both of the tips a 2mm hole is drilled and a fitting, strong wire is cemented in. It makes the rest for the coil spring. To center the spring the wire shouldn't be straight, but bend in the middle.

    On the opposit side a eye is mounted to the carriage inner wall. Therefore to the opposite side of the wall (where the corss rests) a support needs to be mounted. Otherwise the 1,5mm thick wall will not last long to the forces of the barrel weight. 
    It is recommended to bend an eye hold of  2mm welding wire (see picture). This will be placed inbetween two 2mm styrene sheets. As spacers some sheet angles are added inbetween them. They give contact to both sheets. The whole construction is placed into the carriage end box. Therfore a slot for the eye needs to be cut to the inner bulkhead. Simply drill two holes side by side and cut out the space between them. To find the right position use the lower edge of the coverplate. It tells the maximum hight. The eye plate should be positioned as high as possible, to use the spring force best way. Into the space below ballast is filled!
    The biggest problem now is to find a fitting coil spring. Fortunately I had one in my spareparts box. It is good to keep everything!

    Before placeing the barrel in, the barrel angle is needed to be positioned on the right side first. Below of the angle point a layer of supporting sheets is to be added. By adding several layers of styrene sheet the space below the barrel angle point is filled up to the support block inbetween the doublewalls. The reason therefore is to transfer the forces from the angle to the sheet into the block and finaly to the carriage, by cementing all layers plain together. This prevents the parts getting out of shape by wear. 

    For further assembly the parts should be again temporary mounted to a aluminum l-profile. Even better if this is fixed to a ball joint vice too. This lets you turn the whole thing into position with only one move. Also the carriage is held straight and bending is prevented.

    To adjust the barrel straight the angles need to be parallel! Is the angle positioned on the right, the whole gun can be put in place and checked on mobility. The coil spring needs to be unhooked therefore! If everything does move right, the other side can be mounted on.

    Put in first the inner side wall, followed by the outer sidewall and the upper cover. After that cement the left angle in place. So it has to be pushed in from the side it is a little tricky to be cemented in place. Use a thick and slow superglue in this case. Styrene glue doesn't work here proper. Before going ahead let the glue set long enough! Keep the barrel jacked up eventually during that.

    The carriage is now finished almost. All the small parts need to be added now. Which will not be talked about in detail here.

    Before putting on the covers at the far ends of the carriage, the space inside should be filled with ballast and secured with glue or resin. Now the spring can be hooked in and show if the mechanism works. My gun works proper. The barrel keeps in any elevation without shakeing or sinking and can also be lowered completely. Nevertheless don't forget it is only plastic. Don't try to hard.

    A unbelievable way of design.
    What's the sense of it ?
    This is the alternative. A 8mm aluminium tube. The strut was cut right behind the fork support and drilled to 8mm diameter.
    The glued in strut ends shortly before the gap in the support. This gives more surface to cement it.
    Not to be seen good in this picture is the edge in the middle of the strut.
    Cover it with superglue and level it after the glue has set.
    Or simply use a brass strut.
    The ends are filled with superglue and glas bubbles. Do it in layers!
    Again in detail. 
    Then sanding down follows.
    Sinkholes are to be covered with superglue on the toothbars and sanded then.
    Remove the paint beforehand!
    The side walls are spraypainted beforehand with Gunze Mr. Surfacer 500 and then Tamiya XF- 64.
    The carriage put together dry, shows the weak design.
    The carriage is to weak, even for the plastic barrel. However I would reinforce the construction!
    A big loss is the absence of the 
    original drive mechanism. 
    Even a simple blocking is missing.
    The weak bulkheads don't strenghten the carriage enough and tend to let the whole carriage go out of shape!
    You need to be cautious about the support crosses on both ends. The fit is not granted.
     To reinforce the carriage and to adjust them parallel I added 2mm styrene sheet strips as bulkheads.
    Where the angle rests later, the whole construction needs reinforcement to 
    transfer the forces to the carriage.
    I put in a block of Ureol.
     To prevent bending I clamped the carriage to a profile, before I started cementing.
     Where the angle is positioned later strips of styrene sheet reinforce the structure below.
    They are cemented plain to the lower areas.
    To have maximum surface contact the lower side of the angles are filled with sheets, so they rest plain.
    A block made from 5mm styrene sheet assures a parallel guidance of the toothbars.
    To the hole at the side a bolt is fitting, which gives direction to it. It sits centered and can be adjusted in angle!
    The block in place. It will not be visible at all afterwards, but gives proper support to the mechanism. The ends of the toothbars are coupled with a 2mm steel wire then. 
    The carriage with some of the additional, vertical bulkheads. It is obvious how less stability it has. This side of the carriage will be cemented in place after the gun mechanism is fixed in place. Here it is just put in place dry.
    Not realy true to the original, but strong enough for the barrel and not visible at all later. Most important are the horizontal strips. They straighten the whole carriage! Where the angle will rest a massiv block from Ureol or wood is placed to take the forces to the carriage. It is cemented to all surfaces. Above several layers of styrene sheets are glued on.
    This is the way the mechanism works. The coil spring equals the mass, which in original does the hydralic cylinder below. The massiv support to the right is necessary to prevent the bulkhead from tearing apart.

    These are the parts of the eye. Bend from 2mm welding wire. The shape transferes the force to the edges. 
    The 4,5mm plastic sheet holds it in place.
    The assembled eye construction. 
    It brings the force to the carriage.
    The shown position of the eye is important!
    It lies below the edge of the cover and as high as possible.
    The space below should be filled with ballast.
    This shows quite good why the spring needs to be positioned as far up as possible.
    To assemble the barrel mechanism the right angle needs to be installed first.
    Now the side walls can be cemented in place. Again it is clamped to the aluminum profile for straight adjustment.
    The spring should be hooked in only after the glue has set well.
    See the gaps need to be filled with putty.
     The handle was made from 0,8mm brass wire. Don't even think about trying to take the palstic part off the sprue!
    The cradle was screwed to the support with a micro screw from the spare parts box (digital wristwatch) and so stayed turnable.
    Therefore a hole was drilled by hand through the notch. The notch stays!
    The supports for the handrail are made from brass wire and glued to the hinges, which have been cut out beforehand.
    The handrail is cemented on with superglue starting from one end.
    By sanding the wire first the glue sticks better!
    The handrail at the far end stays original plastic.

    Now detailing by assembly instruction follows. Also there is a lot that can be improved or needs to be changed. To be seen above is the cradle for the ammo. The handle in the kit is a 0,8mm thick plastic part, which is impossible to be taken off the sprue without destroying it. So before trying it bend a handle from brass wire first and use the part as a pattern. The cradle is turnable, but has no clamp. And in original in fact has a parallelogram hinge, which turns it in the right direction. I screwed it with a micro screw, which came from a digital wristwatch, to the plate, but first drilled a hole by hand through the notch. Now the cradle can be turned but rests safe too.

    All ladders that go on the carriage should be put in place dry as long as the gun isn't placed in the diorama, because they break away easy!

    The whole handrail is a nicely made plastc part, but it can be foreseen that it will be damaged fast. Who uses the part should keep the paint on the areas that are cemented, to make it a break away joint, which lets the part go off easy and mostly without damage.

    I give it to me the hard way (what else) and replace the handrail with brass wire. Therefore the handrail is bend from 1mm brass wire first. Useing the plastic part as a pattern. The positions for the vertical support struts are marked carefully with a marker. Then 28 supports are cut from brass wire. Cut them 5mm longer then necessary and sand one end first plain than convex. This is easy to be made with the Dremel on a stand and a cutting wheel (Attention! wear googles!). When the groove fits the struts are trimmed to lenght.
    Now the hinges are cut off the plastic handrail (should be done after taken all measures!). The hinges are cut in with a modelling saw careful. In the original the struts go to the hinges, which are flat irons, and are bolted with two bolts. There could be drilled a 1mm hole from above also, but there is less flesh for drilling. That's why I cut them and filed the struts at the lower end to fit. Pay attention to the direction! The strut can be cemented to the hinges easy after that and are strong enough too.

    Are the vertical struts completed they are cemented to the side of the carriage in the holes they belong to. Then the handrail is put on by cementing it starting at one end. The wire should be sanded allover first to give more surface to the glue. After the glue has set the cementing points are sanded to fit and the whole handrail is painted with metal primer. After that tank grey and clear follows with a brush.
    After adding the rest of the small parts it is done. Now painting and ageing follows as well as integrating the model to the diorama.

    Generator-/ Ammunitoncontainer fitting

    For recreation inbetween the ammunition/generator container doesn't suite. When assembling the sidewalls and the bottom it has to be taken care of where to fit them. The bottom goes to a edge above, leaving a free space below. All parts should be checked careful to fit before assembly, especially the front plates. All the add- on-parts are assembled as shown in the instruction. The photoetched parts PE 3 need to be placed with the eye upside (can't be seen in the plan). The big stowing box doesn't fit inbetween the hinges at the container. Here a photo check  is helpful. The most simple way to solve this is to place the box to the holes and cut off the disturbing hinge areas with a knife. Mounting all the handles should be done at least. They are broken off otherwise until painting.

    Before cementing on the deck a bunch of holes have to be filled and sanded even. I still can't understand why they need so much ejectors. The deck has to be dry fit first, because it didn't fit correct. In my case I had to remove the contact edge at one side. The part would have bend otherwise. When building the crossrail version the front edge of the deck B43 must be lowered. Therefore cut off the part like shown in the plan.

    Bending the photoetched part PE 6, which is the exhaust cover, is a little tricky. Assembly to part D21 should be done different than shown in the plan. Cement the lower part PE 12 to the part PE 6 and put it over the Exhaust tube then! Because of the angle in the tube the upper part PE 12 can be put in place after the others are fixed in position. When assembling the crane plattform remember that it can be turned!

    The crane can be assambled like shown in the instruction. Before cementing the winch parts to part B8 they should be testfit to the crane base B2/B30 first, because it can only be mounted in one position! So before mounting the winch parts (which fit in both directions, but make sense in only one way) make sure which way they need to be positioned. To the winch reel B10 the cable is to be wound. I didn't use the included thread, because it seemed a little thin and rough, but a stronger thread, which is thicker and smooth. One end was fixed inside the drum. I notched the edge a little, so I could lead the thread through and put the drum on the end of a brush then. While I turned the brush the thread was wound to the drum nicely. It is not quite clear how many cable need to be wound to the drum, so I ended after half of the drum. At that time I didn't know the exact way of the cable to the crane, because the plan didn't show it. It seemed the cable was lead through the jib, but how? Although I found an internet picture showing the jib beeing closed all aroud, with a v-shaped gap at the top, no picture showed the way the cable went. 
    So I bolted a brass wire to the lower end of the jib, where the bolts are shown. Then the cable was lead through the jib to the tackle and connected to the jib again.  After I finished the job, I stumbled across some photos in my books (should have looked there first), showing a Theodor Bruno Gun and its crane, which is the same kind like the one of the K5. Here I could track the cable exactly. And I did mine wrong! The correct way is to roll the cable from the back of the roll below the jig to the jig roll and then down to the tackle and bak to the jig. Here it is connected inside the jig. Important is that the part PE4 isn't straight, but has a kink in the middle. 
    The lower side of the jig was covered with a sheet of plastic, like to be seen in the pictures below. Also the part PE14 was adjusted after beeing cemented in place. 

    The cranes jig is shown in the instruction completly assembled. The handles B33 and B34 I redid from 1mm brass wire, because one of the plastic parts was already broken on the sprue. So I assumed that the other won't last longer too. The rod B6 was also exchanged by a 1mm brass wire. Why sanding a simple part round? Wire is faster.
    Also the handrail on the crane was redone from 1mm brass wire too. I used the original kit parts as a pattern again and cemented them with superglue.  Always the metal should be sanded before cementing to give it a rough surface and increase glue contact. After the glue has set the edges can be sanded smooth carefully. Then it was placed to the base plate. This one needed to be hand drilled through first.
    I drill the very small holes by hand and not by help of a drill machine, because they have much to high revolutions and the material melts away. Instead I fit the drill to a handle and drill it by hand. This gives absolute control to the process, but takes a little longer.
    Also the single poles where exchanged by brass wire. Same will happen later to the whole handrail on the carriage too.

    The guards PE 5 have been mounted to the container after the  container was painted. Therfore paints needs to be removed from the cementing edge again. To bend the part a ruler and a round stick are useful.

    The ammunition trolley consists of a waggon and a tray, which are not permanent connected! The tray was used in combat to lift the ammo up to the gun from the gunners down below, which prepared the shells and cartridges. The ready ammo was lifted then on the tray to the waggon and rolled to the gun (see pictures below).

    The crane with all brass parts added on. 
    The base is just test fit, because it has to 
    be mounted to the container first (turnable). 
    The handle in detail. The upper etched part isn't bend here jet.
    The etched part after adjustment. Good to be seen the lower side of the jig. The glow comes from superglues used as filler.
     To lead the cable the front bolt in the jig was drilled and exchanged by a 1mm brass wire bolt. But that's not true to the original! See Photos below.
     Here the lead of the cable is to be seen better. It is not shown in the plan.
    To give the container more weight a piece of lead the size of a matchbox was added.
    The box doesn't fit to the lashes, that's why the upper ones were cut to fit the box to the holes.
    The installed box.
    The different shades of grey come from clear coating the box.
    The exhaust in steps.
    The tube was drilled from below and a short piece of wire glued in. This gives more hold to it. The grating is bend by help of the part included in the kit.
    Use care when rolling the part. 
    Also remove the paint from the 
    cementing edges beforehand.
    The part overlaps a little, that is important for cementing it. Before cementig the longside put the end to the bottom part and fix it first, to ensure the exact diameter.
    The done container. Only the middle handrail is from plastic. The rest was
    redone with brass wire.
    The original kit parts were used as as pattern. The crosspoints are cemented with superglue. The handrail ist placed into the predrilled  base.
    Sideview of the container. 
    Next to come is ageing.
    The single poles were also exchanged by brass wire.
    The final look. 
    The dark wash can't be seen good here.

    Historic Pictures

    The prepared granades and cartridges are loaded on the tray.
    Check that the granade is tied down!
    To be seen good is the tray with empty cartriges. See the wheels on it, which are only indicated on the model.
    Picture of a later version of the tray from today. 
    The handles aren't shown on the picture to the right! 
    Also the hooks at the corners are missing. 
    Watch the U-shaped rails and wheels!
    A close up of the tray taken from the picure above. 
    See the wheels are broken through!
    Here the way the cable goes is visible on a 
    "Theodor Bruno" Gun crane. 
    I touched up the way the cable takes to make it better visible.
    Gunners  put on the shell. In the background the crane is good to be seen. It is similar to the K5 crane. See the clamp on the tackle.
    Good to be seen the cable or rope holding the hatch. 
    A hard to find detail. I assume it was a chain used.

    Most pictures are from different sources with unknown copyright.
    The pictures of the crane are taken from "Waffenarsenal" edition "Highlight Band 6 Dt. Eisenbahngeschütze"