Background
In 1942, Krupp received an order to design a new vehicle using existing Tiger components where possible, such as the engine, transmission, steel wheels and track. This vehicle was destined to be the beginning of a Grille (mortar) series of heavy, self-propelled weapons. Originally the vehicle mounted an 88mm main weapon, but soon larger versions were planned, including a vehicle that would field a huge 210mm Mortar 18/1 L/31, called the Grille 21. Full-scale production was slated to start in mid-1945, but the end of the war cancelled any further development.
Grille 21 had its armament mounted on the rail platform inside the hull allowing it to be dismounted if needed. It would be operated by the crew of eight (driver, commander, gunner, radio operator and four loaders). Powered by a Maybach HL230P30 or HL230P45 engine, Grille would be able to travel at maximum speed of 45 km/h with range of 250km. Fuel capacity was to be 1000 liters. This massive vehicle was nearly 40 feet long (with gun), 10 feet wide and nine feet high. Its armor protection ranged from 16mm (side) to 30mm (front). It weighed almost 60 tons loaded, but carried only 3 rounds of ammunition. One prototype with 170mm gun was almost completed in May of 1945 and was captured by British troops at Haustenbeck near Paderborn.
The Kit
The Trumpeter Grille 21, as kitted, is massive – nearly 300mm in length. A beautifully detailed engine and transmission are included and, thanks to three removable panels, can be partially exposed to show off the effort put into these assemblies. Apparently, Trumpeter, which has in the past earned a reputation for giving the modeler exquisite detail only to cover it up with superstructure, is listening! Bravo!
The main weapon, which was intended to be removable in the field, can be mounted in the vehicle or on its own separate stand. Step Twenty-Eight of the instructions address the assembly of the front part of the stand. The rear part swivels down on the model via two metal springs that are included with the kit.
For more information about what is in the box, please refer to the In-Box review I wrote on Internet Modeler. You can find the review on their website at:
After reviewing the instructions I found that I could paint and weather the hull, superstructure sides, main weapon and tracks separately – very handy. I kept this in mind as I worked through the thirty steps of the project.
The first five steps of the build involve assembly of the chassis. The bogies, and there are a lot of them, fit perfectly and align on the main hull without a problem. Be sure to follow the sequence provided in the instructions – several parts at the rear of the main chassis are meant to overlap each other.
Step Four would have you attach the tracks – I decided to attach these later after painting and finishing them, and when I am sure the bogies are dry and solid. The two vinyl tracks are very thick. There is excellent detail on both sides of the track and they take adhesive and paint very well, but I have encountered problems with this track before when building the Trumpeter E-50. Having learned from the other build, however, I applied what I learned to this set of tracks and had better luck. More on this later.
Assembling the Engine and Transmission
There are over 130 parts (!) that make up the engine and transmission. You are given the option to completely cover up these jewels, tease the viewer with two small hatches that can be posed in the open position, or expose a larger portion of them with three removable panels. Trumpeter should be applauded for giving the modeler all of these options. I decided to go for the gusto and build the kit with removable panels. I haven’t worked on such a detailed (in-the-box) engine since building their amazing 1/32 TBF-1C Avenger’s Wright Cyclone power plant.
For the most part, the fit is workable and is reminiscent of those overly-complex Lego kits; parts and parts building into bigger parts and parts. Both the engine and transmission come in layers, so if you wanted to pull either one or both out of the vehicle to place on a workbench in a diorama, for example, you can really show off some detail. That said, I wouldn’t take painting too seriously here – there are a lot of little parts that are covered up by bigger parts. Likewise with minor fit issues and gaps – there is a very good chance that any flaws encountered will simply be covered be another layer, and another. And another.
On page 9 you have what looks like a completed engine. When you turn the page you find out that another 55 parts remain to be added! (Yes I counted – there I said it.) I left parts K7 and K8 off until I fitted the engine into the vehicle so I could orient them to where they would attach to the interior firewall.
Having completed the engine and transmission I skipped a few steps and temporarily installed various bulkheads and firewalls to see just how much of these components would be visible through the removable panels. Unfortunately, even with the panels removed, very little of the engine is visible, and most of that consists of the two big blowers at the top.
Alas, if I had more time I might have painted and detailed these components, but I felt that since so little would be showing I would be better off saving these beauties for a future diorama or King Tiger build. In the end I sealed up the interior and moved on. Sigh…
In Steps Twelve and Thirteen you put together seven crew seats which are a little fiddly. There are several ways you can put these together, all of which, I felt, would work better than what the instructions called for. The instructions would have you glue the seats together then add them to part of the superstructure. I didn’t feel that I would be able to line things up very well once each seat assembly had dried, and to attach them when they were still wet might have resulted in a gluey mess if something went awry. I ended up poking all seven seats into the superstructure and gluing those. When that had dried overnight, I set the
Most likely you will hit a dead stop on Step Fourteen. This is where you realize that there is just no way to avoid filling in some visible ejector pin holes in the sides of the superstructure. If I did not have to finish this build for an article, my Grille 21 would probably have ended up on my ‘someday - when I get around to it’ shelf!
Open-topped armored vehicles have one annoying characteristic that complicates assembly. There is no easy way for the manufacturer to hide mold ejection pin marks – they will be one on side of the plastic or the other, and on these vehicles both sides are visible. This means that the holes (should) be filled and sanded in order to more resemble the real thing (and have any chance of placing in a contest!). The Grille 21 has 26 marks on the two main side panels and another dozen or so on the back of the front-facing plates (of different sizes and depths). I have tried several ways to do this but a friend of mine provided me with the most efficient method that I think produces the best results. It requires a micro punch set, and, if you do not already own one of these handy tools, you should.
Before you assemble any piece that contain ejection pin marks:
- Identify which holes will be visable after assembly, painting and weathering. There is no need to fill holes that no one can see.
- Estimate out how deep the holes are and find a suitably thick piece of white styrene sheet. I’ve found that Evergreen 5 thousandths seems to fit most applications. Make sure the disks will sit just proud of the ejection pin hole when in place, so figure out how thick the styrene needs to be with this in mind.
- Figure out the diameter of the holes and match the proper punch with what you need using a punch that is just slightly smaller than the ejection pin mark.
- Start punching out disks, and glue them into the ejection pin marks with thin liquid glue such as Tamiya ‘green top’ Extra Thin Cement.
- Once dry, mix a little Mr. Surfacer 500 with thinner (I use Gunze Mr. Color Self Leveling Thinner) and apply this over the top of each hole to fill in any gaps. Let this dry for a good few days to look for shrinkage, and sand smooth.
- You may want to air-brush a coat of Gunze Mr, Surfacer 1200 to even out the surface and uncover any remaining flaws.
In Step Sixteen I installed the six supports for the superstructure sides but not the sides themselves. I also left off the front panel. These would wait until after painting ands weathering to be added.
The Tracks. There were several minor annoyances with building this kit, but they were easily overcome with a little work. The tracks supplied with the kit, however, were a disappointment. The detail is excellent, but the thickness of the track and the design of the attachment points proved to be difficult to work with.
First, the tracks are attached with a tab that extends and connects to the other side of the run, but the width of the tab only covers about a half of the width of the track. This means that both inner and outer edges of the track have no means of being attached to one another except by using staples (which I didn’t want to use with an open-chassis design like this). I glued the tabs with super-glue and touched them with accelerator. The tabs seemed sturdy enough to hold so I moved on.
After fitting the track loop onto the vehicle, the thickness of the track created a outward bow that was reminiscent of the old rubber-band tracks from the mid-70’s Lindberg kits. I ended up using copious amounts of Testor’s black-bottle cement and dowels to attach the track to the wheels on each side of the tank. This effort managed to make everything line up, sort of.
In summary, if you want to enter this model in any kind of competition I would strongly recommend using an after market set of link and length track or white-metal track to replace what is provided by Trumpeter. I am told that the King Tiger uses the same-width track, so possibly three of those tracks would suffice for this kit.
Step Twenty-Five – Make sure to test fit these parts before gluing. I looked at the third part of this step about 5 times, and then still assembled it wrong. Or the number call-outs are wrong. Whatever the case, I suggest you assemble it and once you are sure it fits in the base, glue it in place. If you intend to mount the main weapon in the vehicle and not on its own stand, the whole affair, thankfully, is hidden from view.
Photo-Etch
Trumpeter included a small sheet of photo-etch that contains grill covers and louvers for the exhaust blowers on each side of the engine. The instructions call for installing the blades with the smallest one the farthest away from the fan. Looking at the finished assembly, however, this looks backwards. The smallest one looks like it should be the closest to the fan. Without any reference material handy I decided to follow the instructions.
Painting
The ‘Painting and Marking Guide’ shows a factory-raw ‘Red Brown’ and contains call-outs for Gunze Mr. Hobby Aqueous acrylics, Gunze Mr. Color Lacquers,
I decided to use these same colors but paint the main weapon late-war German Yellow as shown in photos of the assembled model on the side of the box.
Because of the open design of self-propelled guns I decided to paint and weather the main chassis, two large superstructure sides and front panel, and the main weapon rack separately before final assembly.
I worked with these same tracks on the Trumpeter E-50, so I decided to paint and weather the tracks prior to attaching them as well.
I started with a primer coat of XF-69 NATO Black over the entire model, including the wheels. The tracks are already jet-black from the box. This primer coat will give the tank a ‘dark’ look that (in my opinion) is appropriate for armor. I concentrated on the nooks and crannies – complete coverage. I let everything dry for at least 24 hours.
I sprayed the tracks with a mixture of Tamiya XF-68 NATO Brown and XF-9 Hull Red, making sure to leave some of the original black color showing through. I followed this with a random coat of Tamiya NATO Black and Tamiya NATO Brown, leaning toward the black.
For the superstructure, I followed the black primer coat with a base coat of XF-9 Hull Red. Over that I sprayed a post-shading coat of 40/60 ratio Model Master Enamel Raw Umber and Model Master Enamel Rust.
For the main gun assembly and rear breech platform I followed the black primer coat with a base coat of Tamiya XF-60 Dark Yellow. Over that I sprayed a post-shading coat of 50/50 ratio Tamiya XF-60 Dark Yellow and Tamiya XF-55 Deck Tan.
Once these colors were dry I sprayed on a liberal coat of Future Floor Polish (an acrylic) on both the superstructure and the weapon assembly and let that dry for two days before applying washes.
Finish
I applied a generous coat of Future floor polish to the entire vehicle to prepare it for an oil wash (no markings are included in the Trumpeter kit or present in any of the drawings).
After the Future had dried for 48 hours, I mixed a filter of Mig Abt110 Black and Mig Abt080 Wash Brown oils with Mona Lisa Paint Thinner and gave the entire model a light coat, concentrating on the wheels and the various hull detail and protrusions.
Once the oil filter was dry I followed it with a wash of the same oil mix, only with less thinner, and used a small brush to apply the wash to just the areas that needed it.
Next I sprayed random vertical streaks of NATO Black and Model Master Rust to the superstructure. I finally gave the entire vehicle a coat of thinned Testor’s Dullcoat. This dulled up the surface and prepped it for dry Mig powders.
I highlighted the tracks with a dry ‘loose’ mix of MIG PO25 Standard Rust and MIG PO23 Black Smoke pigment powders using an old trashed set of brushes I keep specifically for this kind of work. I didn’t combine the colors too much; I want black on parts of the track and black-rust on other parts - nothing consistent, like real grime and filth. Once the powder was on and set, I used my finger to apply MIG P231 Gun Metal to all the areas that needed it including the surfaces of the tracks that actually touch the ground and the main drive sprockets. Finally I used a silver pencil here and there, along the inside of the tracks and teeth where the wheels have rubbed against the track.
When everything looked the way I wanted, I carefully assembled the hull parts and attached the infra-red sighting system to the top of the turret.
Conclusion
Working on this kit, I could not help but wonder where Trumpeter came up with the source material for so many pieces they included in the box. This vehicle is not a variant of some other late war German machine, like a Panther or a Mk IV or a Tiger. It is a completely new design, literally one of a kind. Unlike several other prototype armor kits, this offer by Trumpeter is absolutely superb in its detail and engineering.
I wish I had been able to put in more time to focus on the exquisitely rendered engine and transmission, and possibly even given the finish a combat scheme.
I recommend this kit to anyone who likes to build and finish big-time self-propelled guns. The size of this vehicle sitting on a table demands attention!
I would like to thank Stevens International for providing this sample for review, and to Internet Modeler for giving me the opportunity to build this kit.