Modelling > Engineering Dept.
Mineclearing Flail Tanks for Ukraine
apophenia:
Tank-Based Mine Flail for Ukraine? - Option #2
The Bundestag has proven slow to respond to realities on the ground in Ukraine. That said, I must acknowledge that its a big ask to request all of Germany's flail tanks. Even if Berlin were willing, without Keiler, the Heer would find it impossible to maintain its own skills level. So, the next option is finding a suitable substitute for the existing Keilers.
Since Rheinmetall already owns Leopard 1A5 hulls, adapting some of those for the ZSU flail tank role would seem to make sense. So, Option #2 proposes adapting Rheinmetall's Keiler system to the Leopard 1 hull.
Advantage: The Bundestag has already approved the export of Leopard 1s to UA.
Advantage: The ZSU now have experience with Leopard 1, Dachs 2, Wisent 1, etc.
Downside : Extra time is needed to re-engineer the Keiler system to suit a new hull. [1]
Downside : Engineering challenges equivalent to producing a Leo 2A4-based conversion.
Advantage: FFG seems highly motivated to shift its stockpile of Leopard 1A5 hulls
That final 'Advantage' is by way of suggesting that there may be a sub-contract opportunity here. Rheinmetall gets to be prime contractor because they own the rights to the Keiler system. That flail system itself could be farmed out to one or many parts of Germany's burgeoning construction equipment specialists. Hull modifications and final integration could be the role of FFG.
Work spread around, Bundestag deputies happy.
_____________________________________
[1] The proportions of the Leopard 1 hull are significantly different from those of the old M48A2G.
apophenia:
Tank-Based Mine Flail for Ukraine? - Option #3
This is a 'budget option' which also happens to avoid dealing directly with the Bundestag. The concept is simple - produce a crude, easy-to-manufacture jib for a flail drum tailored to those surplus Leopard 1 hulls. For my example, I have pinched a jib/drum from a WW2 Sherman Crab V. Other historical examples made be better but this ad hoc 'Leo-Krab' conversion gets the idea across.
Advantage: No valid patent claims exist for Sherman Crab's 80-year-old technology.
Downside : The state of the art has improved considerably since World War Two. [1]
Advantage: The familiar-to-ZSU and readily-available Leopard 1 hull is employed.
Downside : Power take-offs must be engineered; or a dedicated drive engine installed.
Downside : Sherman Crab tended to over-burden front suspension units. [2]
Inherent in that last 'con' is the inability to retract or rotate the jib and drum. As a result, that burden is on the forwardmost suspension regardless of whether the flail drum is operational or not. [3] However, put bluntly, survival rates for such vehicles in Ukraine will be low. A 'mobility kill' is far more likely to be the result of stacked mines than any mechanical failure.
_____________________________________
[1] Obviously, there is nothing to stop the integration of modern concepts into this design. At the simple end, perhaps the 'dumbell' hammers from the Keiler are adopted instead of old-fashioned 'balls'. At the more sophisticated end, perhaps the mechanical drive is ditched in favour of Aardvark's hydraulically-drive RACE concept.
[2] One partial solution is illustrated in post #3, above. On its Leopard 1-based AMCV, Norway's Hägglunds Moelv AS mounted stabilizing roller wheels at the hull rear. This would not relieve weight on the front suspensions directly but it would prevent the vehicle from 'bunny-hopping' while the flail was in operation. This would take some of the strain off the suspension while also ensuring the proper height of the spinning drum.
[3] Although even more complex than the options above, the only realistic solution to forward suspension overloading is rotating the jib over the hull. The mounts for rotating jibs - as seen on the Keiler and Norwegian NM189 Ingeniřrpanservogn - are very complex. A somewhat simpler folding jib option was seen on the postwar Centurion 'Toad' where central hinge points allowed the jib to fold back over itself. Of course, all such potential improvements come at the cost in time.
apophenia:
Tank-Based Mine Flail for Ukraine? - Option #4
This is similar to Option #3 in that it proposes building flail systems tailored to Leopard 1 hulls. But, whereas Option #3 copied the WW2 Sherman Crab V, Option #4 nudges the technology closer to the 21st Century.
To me, the hydraulically-driven Aardvark RACE A system prototyped in 1992 is still the most advanced mine flail concept. Removing mechanical drives - shafts, universal joints, bevel gears, etc. - greatly simplifies the job of creating a new jib and drum system for a flail tank. And, for a time-urgent project, RACE A's split-in-the-centre articulation can also be ditched. [1] In its place, I am imagining the entire jib 'hinging' to fold back over itself in the manner of the old Centurion 'Toad' mine flail.
Advantage: The most up-to-date of (single drum) mine flail technology.
Downside : Must be engineered from scratch to fit MBT hulls like Leopard 1.
Advantage: Rotary- and swivel-type hydraulic fittings already exist.
Advantage: Hydraulic drive systems add weight but much simplify mechanics.
Downside : As with Option #3, front suspension units will be overloaded.
Advantage: Rear-mounted auxiliary engine shifts hull balance further aft.
Advantage: Side-port swivel fittings allow jib/drum to be rotated over hull.
For the image, I have depicted a hydraulically-driven version of the mine flail system from the Aardvark JSFU. However, I have omitted RACE A's articulated-joint folding. Instead, as note in the that final 'Advantage', a simple pivot point on the upper glacis allows the entire drum jib to rotate backwards over the crew 'doghouse' to rest above the rear engine deck.
Okay, I'm finally done. The floor is now open for suggestions, corrections, brickbats, TLDR yawns, etc.
________________________________________
[1] As a reminder, Aardvark's RACE A compacted for transport by folding into a 'V' shape from a centre-line articulation of the flail drum. Very clever but replicating that now would just add to development time.
GTX_Admin:
Relevant to this topic: Czech crowdfunding campaign raised money for mine-clearing vehicle for Ukraine
apophenia:
--- Quote from: GTX_Admin on September 24, 2023, 04:08:02 AM ---Relevant to this topic: Czech crowdfunding campaign raised money for mine-clearing vehicle for Ukraine
--- End quote ---
Thanks Greg. I love that this was under the Dárek pro Putina ('Gifts for Putin') campaign :D It's a great name but they are also providing a lot of good kit - from basic ammunition to T-72s to drones (including CZ Bivoj TUAVs).
I also like the pragmatism of a Czech crowd-funding campaign purchasing Slovak equipment - Božena being a product of Way Industries of Krupina, Slovakia (about 180 km east of Bratislava). Of course, there is still CZ content in the Božena 5 - like its Tatra engine.
-- https://way.sk/en/produkt/bozena/
At last report, the Dárek pro Putina-funded Božena 5 was going to be doing demining in liberated areas of Kherson Oblast.
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version