OTW Molch 1/9 scale - The multiple rebirths of a classic

[subicman]

The Molch (Salamander) was, for those who do not know, the Kriegsmarine’s first attempt at a midget submarine. 393 of these one-man submarines were completed solely at AG Weser in Bremen, Germany from 1944 to the end of the war. These boats were wholly electric, powered by a battery array and the motor section from a G7E torpedo. They had a relatively short range (64 km), a low speed (5kts) and carried two G7E torpedoes slung low to either side. They were to be transported to makeshift operation bases via truck and trailer and could be launched by crane or by floating off the trailers.






Despite high hopes by the Kriegsmarine, operationally they were unsuccessful, and the K-Verbande (Small Attack Unit squadron) eventually regulated them to training vessels for the other more successful midget submarines. There have been several surviving examples on display in museums, however recent searches have revealed that many have been removed from display.


Molch on display in Portsmouth Naval Shipyard in Kittery, Maine. Scrapped in the 70's.

History lesson aside, OTW Designs has an offering in 1/9 scale located here: https://otwdesigns.com/molch/ although it looks like Bob Dimmack is offering them as a special order at this time. On the page is a uncredited picture of a customer finished model. I have included that picture below for those who do not follow the link. Why is this picture important? We will cover that shortly.


OTW Customer finished Model.

Fast forward to ~10 years ago, when Subron4 had a larger member base than it does today, and I was still active duty. A member of Subron4 at that time, Kevin Price, has come into possession of a well-used and abused OTW Molch. She was in rough shape, the ownership chain of this particular model was pretty hazy, and prior to Kevin, I am quite sure that Tony G. had it pass though his hands, and I think Myles may have owned it at one time. Rumor had it that this model had been built in the UK, but I never had confirmation of that fact, despite talking to Bob Dimmack about it on a few occasions.
When I took possession, the torpedoes were barely held on, missing fins, the warheads were not attached, and the torpedo bodies were oblong from having the hull sit on top of them for many years. All the brass torpedo details were loose and failing off. The hull itself was in decent shape, but the upper hull to lower hull indexing system was broken and several cracks were starting where the horizontal stabilizers attached to the hull. The hinges for the very large stern plane were pulling out of their mountings and the rudder skeg was trashed.
Attached is a picture of the model as I received it. Does it look familiar? It should, it is the one and only customer finished model in the picture on the OTW site! Thus sets the scene for the 1^st rebirth of this classic model.

[sam reichart]

Bob has always been proud of that model. His Seehund (one of my favorites) always got the glory over the Molch. I can't wait to see what you're going to do with this one.

[subicman]

Sam,

Do you mean to imply that Bob himself may have originally built this model? I know he is proud of his kits, I was not aware he may have built some.

As for the destination of this model, I refer back to the title, multiple rebirths. I think that the membership might enjoy the journey. When I started in model submarines in 2007, my skills although good in model railroads, was not there yet in RC ships, let alone subs. I had an advantage of having the knowledge from serving on them, but executing that knowledge in the model world took some time and coaching.

I have had this model now for over 10 years, she has been one of my consistant runners, and has seen many hours in the water and has had more than one refit. Some for good reasons, others for tragic reasons.

I recently recovered a lot of images from an older laptop of mine, and found a treasure trove of past memories, some of the pictures I even forgot existed.

I plan on using the thread to document the 10 years of my ownership of this model. Some things I don't have pictures of, but my memory of what I did is still strong. Other areas my memory is about as hazy as the chain of ownership.

I will have another post later tonight that will document the 1st rebirth (refit).

Tim

[sam reichart]

I can find out from Bob if he did indeed build it. I know he's built his own kits. He and I chat frequently...

[subicman]

Picking up where I left off yesterday, it’s July of 2012 and I have just sealed a too good to pass up deal with fellow Subron4 member, Kevin. I have in my hands a well-worn, beat up OTW Molch in 1/9^th scale. Damage to this model is broad in spectrum, but not a non-starter for refurbishment. I am delighted to find out that it is in fact the poster model from OTW’s website. At that time, not much was known by me about the pedigree of that particular model.

I have, in the last day found out that my suspicions were correct, and that Tony G. did work to it on behalf of the original owner Myles Yancy. This work was performed around 20 years ago or so. Tony told me in an email this morning that he had built the torpedoes for Myles and Myles had painted them, but I still am not sure if Myles was the original owner/builder of the model. How Kevin came to be in possession of it, I cannot recall, and I lost touch with him when he left the Navy and moved to New York.

Anyway, moving back to the refit. At that time, I did not have a fully operational model shipyard. My basement room that I use now did not have lighting, had a severe moisture problem, especially when it rained. The whole basement had flooded out in spring, 2010 with the severe weather that hit New England that season. I was slowly but surely chipping away at solving these issues but being active duty and on an operational boat at that time did not help my cause any. My wife didn’t like it, but I did a lot of my work bouncing back and forth between the living room floor and the picnic table on my deck.

Below are some pictures of the issues with the boat. What I did was to try to repair the cracks, installed magnetic hold downs between the hull halves using rare earth magnets, built a new rudder skeg and totally rebuilt the torpedoes. The tricky part was trying to re-attach the hinges for the large stern plane. This would eventually become an issue in the future, but that is for another post. I also made custom weights that were within a few tenths of a gram of each other and installed them into the torpedoes. This would help and hinder me in the future.

I apologize for the picture quality, they are from a camera phone that was new back then, but not to today's standards.


Hinge repairs


The above picture is of the lower hull magnet installation


New Skeg


Upper hull magnets install


Torpedo work

I had consulted Bob around this time to obtain some replacement parts, and he provided, and as I would find out over the last ten years, excellent service as always.

Tony G. took the OTW cylinder and refreshed all the seals and o-rings and refreshed the water probes in the ballast tank. He also built me a battery compartment that is still to this day, more than enough to run the model all day on one charge. In fact, this year’s post storage charge analysis came back with a calculated capacity of over 94%!



I finished the refit by painting the old girl in a new camouflage scheme. If you look carefully at the line of Molch’s in the first post, you can see that they had several paint schemes, solid, splotch camo like the model was originally painted and tiger stripped. I opted for the tiger stripping using colors that roughly approximated German Schiffsbordenfarbe III Grau and Hellgrau 50/Dunkelgrau 51. The color schemes for WWII U-boats have been highly debated over the years and a few documents have come to light that described the paint measures at that time. After some talks with Jeff Larue, I felt confident that this was an accurate as possible scheme. To maintain a little of the originality of the model, I added adhesive decals from a P-40 Warhawk model to maintain the shark's mouth scheme.

Another highly debated topic is the paint scheme for the G7E torpedoes. I personally liked the original green and metallic paint scheme and went with it. Was this an accurate color choice? I didn’t know for sure and at the time it was one of the best answers that could be found.





After repairs were completed, I commissioned her into my model fleet and that brings me a logical close for this post.


Here you can see the decals on the bow

Until the next post:
Tim

[subicman]

I can find out from Bob if he did indeed build it. I know he's built his own kits. He and I chat frequently...

Sam,

If it happens to come up when you talk with him next, I would be appreciative!

Tim

[subicman]

The model submarine season up here in New England runs from Open Water season (early May) to Hard Water season. The first meet of open water season was always at SubRon4 member Bob Harris’s house to open the test tank (In ground Swimming pool) for the summer. The start of hard water season is usually signaled by the final run of the season, which we try to get on the Submarine base at North Lake. Some years we get it and other we don’t, either way our last run was usually around Labor Day, and we would put the boats in winter layup.

The rebuild of the Molch took up the better part of 3 weeks and the commissioning into my fleet happened in early August 2012.

During this time frame I was stationed aboard one of the Navy’s newest Virginia class submarines, USS New Mexico (SSN-779). We were fresh to the fleet, just over a year out of PSA (Post Shake-down Availability) and we were in and out of port quite a bit. For those who have previously served, you know that 3-5 weeks in port is a long time for a fast boat.

I was able to get a Molch trim run in, I believe at the test tank, then I was off with the Boat for a short visit to Annapolis for Midshipmen awareness and then continued to Norfolk, VA for a COMSUBFOR/COMSUBLANT change of command. We returned to Groton, well after the close of Open Water season.

The rest of 2012 and all early 2013 was spent working up for New Mexico’s maiden, and my final deployment. Being senior enlisted, I spent a good portion of the time honing my Pilot skills in the Dive and Drive trainer and very little time working on models. We departed on deployment in early February, and I returned stateside in late July to start the retirement process.

At this point, I was on terminal leave and was able to get a bath tub trim and a couple runs in prior to the start of Hard Water season. That year the run was held at North Lake on the base on September 7^th and 8^th.

A quirk with the boat I noticed during those runs was that the propellor had a wobble to it and it made an awful sound when being run at full speed. I knew that the prop shaft had a heat shrink tube around it to mate the WTC output shaft. The coupler that was in use was not a 4mm-to-4mm coupler and I hadn’t fixed that during the refit.

Attached are some pictures of that run and If I can figure out how to upload video I will. One of the things you are bound to notice is that there is a Velcro band around the torpedoes and the hull. This goes back to my statement in yesterday’s post of the weights in the torpedoes being a hinderance to me at times. The main ballast weight shift from the hull to the torpedoes had put a strain on the torpedo mounts and they started to pull out of the torpedo bodies. The strap was a stop gap so I wouldn’t lose them in the Lake.


This is one of the torpedo mounts, there are 4 of them (2 per fish), they are a 4-40 threaded insert that is epoxied into the the torpedo bodies. A 4-40 screw and washer are inside the body and tightened down to form the stud portion. They are then fastened to the hull using a nut and washer inside the boat.


Sitting on the bottom at the edge of North Lake


Underway on the surface




I'll try to get the video up, but that's it for tonight folks

Tim

[subicman]

Here is the link to the video:

Listening to the video after all of these years, it seems that I knew at that time that it was built by Myles. I also was reminded that the original re-paint colors were Testor's Model Master Luftwaffe colors. Maybe my memory isn't as good as I thought.

Tim

[subicman]

September 2013, the Molch has been been in the water operationally and made it's public re-debut at North Lake on the Sub Base in Groton. I had identified a few issues that needed to be addressed, but those would have to be addressed over winter lay-up as our Hard Water season had started.

I retired from the Navy with 23 years service at the end of October that year, and started my first civilian job a few weeks later. During this time I started a 1/96 Scale Shipyard Alfa model and a coinciding build thread with it. A week before Thanksgiving, my wife of 17 years suddenly passed away from un-diagnosed heart disease and threw everything I have ever known into dis-array. It was about this time that I dropped off the SC forums although I still went to my Subron4 get togethers over the winter when I could, but all real work on my models stopped for about 6 months.

When it was closer to the start of open water season, I decided to correct the issues that I had identified the year before. Any other model building was still on pause, as I wanted to get my completed boats running again. I also decided to retire my Thor Design 1/96 Sturgeon class, USS Pogy around this time, so Molch was truly going to be my only runner.



Those issues that I identified where the loose torpedo mounts and the wobbling shaft, and thus begins the first mini-refit for the boat.

For the torpedoes I un-mounted them and re-epoxied the inserts into the torpedo body and added larger diameter washers to spread the load better on the hull and the torpedo body. The shaft coupler was removed and I pulled the prop shaft out of the boat. I found that the forward shaft bearing inner diameter was 5mm versus the 4mm that the prop shaft was. I ordered some stainless steel dental tool sealed bearings in the proper size and replaced the one that was improperly sized. I looked at the dog-bone couplers available at the time and found that they were too short, or wasn't available in the correct size. I also thought about making my own on a little lathe that I had come by, but ultimately found some telescoping stainless steel shafts for RC Race cars that fit the bill very nicely.



Around this time I bought another Classic OTW model, the German Midget Hecht from Tony G. And by classic I mean the same model that Bob has up on his website as the finished model picture for the model kit. Here is a shot of her at the pond 5 years ago.



That about wraps it up for tonight, Molch and Hecht became my goto running models and went to the pond/pool with me when Subron4 would get water time over the next few years. Tomorrow I will get into the second Refurbishment/rebirth of the Molch.

Tim

[sam reichart]

As you mentioned above, I did verify with Bob that Myles was the original builder of the Molch. Per Bob, that photo was taken at Groton.

[subicman]

Sam,

Thank you for that info. I seems that North Lake has always been home territory for this boat.

Tim

[subicman]

2014 came and Molch is running better than in the previous year. No more velcro strap for the torpedoes, the shaft wobble and noise is gone and the boat is running pretty smooth Tony G. has instructed me on how to properly care for the ballast tank level probes.

The only notable thing about this year is that I started at Electric Boat in Groton. I started as an Electrical Draftsman, and rapidly made to Designer on the Hourly side of things, and then after about a year made the jump over to Salary as an Electrical Test Engineer. This was an Engineering position based on experience with an Associate degree.

The next 5 years sees pretty much flawless runs with the Molch until fate creeped into my world once again. In early 2019, I am prepping the Molch for running season and the stern plane separates from the horizontal stabilizers at the hinges. Morale of the story is that Bondo and the Glazing Spot Putty that I used during the initial refit did not like the extended submerged conditions it was subjected to. That combined with the fact that I may have used not so fresh materials when I did the work resulted in the dilemma I found myself in now. So began the 2nd major refurbishment of this model.



Above you can see the areas where the hinges were. The hinges that were originally used were the Dubro Nylon hinges with brass pins. There is nothing wrong with these hinges fundamentally, however the attachment methods were a little on the lite side. They were epoxied in only and then body filler smoothed over. I perpetuates this error by fixing the body putty only during the first major refit.

Bondo may get a bad rap in these circles, and other body fillers are recommended, but I learned that they are all are basically the same, a talc base thickener in a polyester resin to bind it together. The problem with talc is that is is hygroscopic, and submergence in water doesn't help this fact any. This can still happen despite being coated in several layers of paint. So the Bondo failed due to moisture and then the epoxy that was originally used failed in its adhesive properties, and the nylon hinges pulled out of the sockets.

I thought about other solutions such as a brass piano hinge on each side, or small brass utility hinges, but in the end I got the Dubro hinges again. This time I roughed up the nylon surface on each side of the hinge and I drilled pin holes and pinned each hinge into place using brass rod.



I used woodworking clamps to hold the stern plane in place while I aligned each of the hinges and I used a marine grade epoxy to fasten the hinges in place.



I used Bondo over top of that to fair things in. Now, I know what you are going to say, "Tim you just said that is a reason it failed", and you are right, but I learned something about Bondo in the meantime. If after you apply it and sand it, you coat it with a thin coat of finishing epoxy, it gets sealed against moisture intrusion. You can then paint right over it and not have to worry about it getting brittle for that reason. After you let the epoxy cure that is.... A few more hull repairs using fiber glass and epoxy resin in a few locations and we were ready for another paint job.

I decided I liked the tiger stripes and stayed with them, but the Testor's paint was hard to come by at this point and the paint job was done using 2 different colors of Rust-oleom sandable primer and a coat of matte clear to seal them in.



The pictures above show that a full range of motion was still achievable after the repairs.



Thus ends the 2nd Major refit of the Molch. She sees the water again a few times before Covid and other things.

The next few posts will be of the 3rd and current major refit of the boat. The format is going to be a little different than what I have been using to now. Working at EB in Construction Engineering, there are meetings upon meeting at which statuses are thrown around for different projects. One of these meetings is called the Breakfast Club Meeting and happens once a week. During this meeting the department managers and Directors report the status of each contract under their cognizance to the President and VPs of the company.

When we lost our dear friend Bob Harris earlier this year, the remaining members of Subron4 decided that we needed to start meeting again, if for anything to reminisce about the good times we had all together. After our first monthly meet, the build bug came on again and, trying to interject some fun into our emails, I started reporting my project statuses in this format, and the guys have loved it.

Till tomorrow
Tim

[subicman]

Over the next few years, I get remarried, I adopt my wife's daughter, 2 of my kids leave for college, I earn a BS in Electrical Engineering and life goes on. Subs eventually get shelved because of COVID, no meetings out of caution for each other's well beings. When we finally started to get back together, i decided to start my OTW Type XXIII, and had the keel laying ceremony and designated her the U-4712.

April 6th of this year. I received a phone call at work from my wife. She tells me that I am going to be mad, and after some hemming and hawing I get out of her that my submarine model fell off the shelf. I at first thought that it was my USS Pogy, but I remember that I screwed that stand to the shelf and the stand was sufficiently deep enough to withstand a car trip, so it couldn't be her. She informs me that it was the lower submarine in the bedroom...….Molch!. When I got home I gave her a precursory inspection to determine the damage.

Molch had fallen off the shelf approximately 6' and suffered moderate structural damage. The WTC seemed to be intact, but I figured it would need a pressure test to be sure. The cockpit was broken off, the periscope fairing separated from the cockpit, and the aft lifting padeye and the rudder skeg snapped off. There was cracking in the upper hull but amazingly the aft stabilizers and the stern plane were intact as well as all of the tiny brass bits on the torpedoes. The torpedo attachment system needed tightening but was still good! I figured about 2-3 weeks in drydock to get her right. Hence start the Breakfast Club meeting briefs.

Afternoon of 6 April:

Molch has been placed in drydock, post docking hull inspections are completed. WIPS (WaterTight Intergrity Permits) have been opened, TGIs (Task Group Instructions)are being written and routed through the appropriate chain, expect work commence late 2nd shift today. STO (Ship Test Organization) is in process of evaluating control, propulsion and ballasting systems. Internal inspections found the battery compartment mounting was cracked.

7 April:

The trades labored through 2nd shift and got the cockpit and the lifting padeye re-attached. The upper hullcrack was also repaired. They are currently prepping the periscope for repair, pending NDT (Non-Destructive testing) of the joints for the cockpit. The bums down at STO waited until too late to start systems checks, and found out that a battery charge was required. The CO wouldn't authorize one that late. Battery charge scheduled for today.

9 April:

Breakfast club report:


Radio Command systems:
The Futuba T9CAP radio control system has undergone a balancing charge of the battery and checks of all functions on both 75Mhz channel 66 and 78 with no issues. All operational parameters have been verified against MS Molch and MS Hecht (MS = Midget Submarine) configurations, and TYP XXIII configuration has been generated.

Repairs to MS Molch:

S/F determined that a test discharge was required per their PM schedule. The CO authorized and S/F conducted a normal charge, followed by a test discharge, and finally conducted an equalizer battery charge. After charge analysis placed the main storage battery at 95% capacity.

STO finished command and control checks and compartment pressurization checks on MS Molch with satisfactory results.

Trades continued upper hull repairs and landed the periscope and fairing. During the evolution the fairing was damaged and trades are in process of repairing the damaged section. In addition the Persplex dome was found to be not fastened correctly while being cleaned and polished, this has been repaired.

Further hull inspections have revealed that the vertical stabilizer mountings were indeed stressed and damaged. Trades and riggers have removed the vertical stabilizer and the hull section in this area is being reinforced. Due to the extensive hull repairs, SUPMODSHIPS has authorized painting and preservation of the entire hull. Weapons systems unmounting to be conducted within the next few days to support this.

Lower hull repairs are still being evaluated, and engineering is tasked with re-designing the battery compartment mounting system to provide more strength and stability. Work is expected to commence later this weekend, early next week.

TYP XXIII/MS Hecht:
Construction of TYP XXIII class, U-4712 is in progress. Work was halted while awaiting plan Rolle from Germany, however those have arrived and Trade work will recommence. The upper rudder carrier was removed from the upper hull and reinforced. Materials for the rudder linkage arrive from robotshop.com and trades are working on an installation plan.

MS Hecht Command Module upgrades to support TYP XXIII operations have been completed and STO conducted command and control checks on MS Hecht systems module and found that there was excessive control linkage binding. The upgrades to Type XXIII control system standards allows for both stern and bow plan usage and is a crucial upgrade which is required to complete the U-4712 project.

Work then commenced to isolate these issues and rapidly found under-lubrication and a bent control rod. These were rectified and all system operating parameters verified SAT.

MS Hecht post storage/pre-operational checks have been completed and all hull systems are intact. S/F reports that a refresher charge and test discharge of the main storage battery will be conducted this coming week.

V/r
Tim
VP of Model Submarine Projects

[subicman]

14 April:

Breakfast club report:


MS Molch repair status:

Repairs to the hull have been on-going for the last several days. Upper hull repair has been completed with all strengthening having been installed, the periscope fairing repairs completed, and the scope landed.

Lower hull repairs were completed, however when aligning the rudder skeg, it was discovered that the propulsion pod mounting was cracked. This discovery necessitated the Trades to remove the propulsion pod and strengthen the attachments. STO had to re-algin the propulsion shaft and bearing upon re-attachment. Once completed, repairs to the rudder skeg were concluded.

During weapons removal, it was noted that several of the weapon mount hardware sets were exhibiting a loose fit. The attachment points were refreshed, however during weight testing, the Riggers dropped a weapon! The weapon did not detonate, however the warhead separated from the the torpedo afterbody along with minor exploder damage. The torpedo will have to be sent to the depot for repair. Luckily, no loss of life occurred. A Team Learning Session has been convened to determine the root cause of the incident.

Due to inaccessible areas becoming accessible upon weapon unmounting, upgrades to the weapon mounting points on the hull have been performed. Other Shipalts for upgrading upper hull to lower hull attachment and stern plane/ rudder swing clearances have been installed.

Painting and preservation of the hull is scheduled to be conducted this weekend, pending weather. Overtime has been authorized for the trades during the holiday. Upon painting and preservation completion, installation of the newly designed battery compartment mounts will commence, weapons systems re-mount and follow on re-installation of command and control systems soon after that .

MS Hecht:

Post storage battery operations have been completed and test discharge/equalizer charge data shows a 93% battery capacity.

Typ XXIII U-4712:

Translation of planrolle from German is in progress. Purchase orders for new oilite bushings has been cut, and material is in route.

V/r
Tim Fisher
VP of Model Submarine Projects\

[subicman]

21 April:

MS Molch repairs:

Paint trades took advantage of the nice weather prior to the Holiday and got a good prime coat on the hull. Unfortunately for them the weather turned , so no OT authorized for painting over Easter. Trades are looking forward to the nicer weather expected going into this next weekend to start with the topcoat.

The weapons depot took custody of both weapons, damaged and un-damaged and stated that they would be issuing replacement weapons for MS Molch in the near future. Indications from the depot are a possible overhaul of both weapons. Estimated turn around time 1 to 2 weeks.

MS Hecht:

MS Hecht is 100% ready for post storage launch. If weather permits for training basin (My pool) opening prior to first operational run, trim dive will be conducted in the training basin.

Typ XXIII U-4712:

Rudder bearings have been received. Work has slowed due to other shipyard commitments outside of submarine building and repairs.

TYPE 214:

The Type 214 project was recently discovered in a dusty part of the shipyard, abandoned in place. This dry hull concept is 100% built but had major issues during sea trials. There are talks between the yard and SupModShip of a contract to convert her to conventional OTW dive systems and re-commissioning her later this year.


Tim
VP of Model Shipbuilding