OK. So the Land Raider ... 350mm of conventional steel armor, 91-95mm thickness. The Thunderhawk... 200mm of steel armor equivalent.
Now, I present to you the Predator of the Rhino chassis. Frontal armor rating of 13 in the game, it's the Space Marines' version of a battle tank. The details of the description are interesting. Mike Dicenso may find it helpful for quantifying the layers of a SM's armor.
Imperial Armour 2 wrote:Due to its STC roots, the Rhino can be constructed using locally available materials. Most Rhinos are constructed with a bonded ceramite plasteel hull over a cast plasteel hull, although others use composite carbon compounds or conventional hardened steel, depending on their origin. A Rhino's engine can run on almost any kind of combustible fuel.
Regular Rhinos - which are
not unarmored - can be built to specs using conventional hardened steel armor.
Imperial Armour 2 wrote:The Predator's armor is constructed of three main layers. The inner layer provides the main protection. The inner layer provides the main protection. Its a bonded ceramite/adamantium alloy which provides protection equal to over five times the width of conventional steel, whilst being lighter. The second layer is a reinforcing thermoplas with a sub-dermal energy dissipation fibre mesh, providing protection against extremes of heat and radioactivity. The outer layer is a non-magnetic acrylic identification sheath. In all, this corresponds to over 200mm of conventional steel on the front of the vehicle.
The Predator has a 65mm layer of armor. It sounds like - from the "over five times... over 200mm" correspondence that the inner layer is 40mm. The outer layer is a layer of
paint, maybe 5mm, meaning the second layer should be ~20mm.
Curiously, if we assume that thermoplast radiation protection plus paint layers take up the same thickness on the Land Raider, that leaves a peak thickness of 70mm of titanium, plasteel, ceramite, and adamantium, which corresponds
presicely to the proportion of conventional steel armor the two armors are being compared to (and, by analysis of probably rounding on the "more than five," suggests we are only a little bit over five times the durability.)
So a lascannon can, assuming "equivalent protection" really means "equivalent protection" for most tradition types of attacks, penetrate 350mm of steel armor, albeit not necessarily 100% reliably. I assume the beam impact must be close to orthogonal to pierce Land Raider armor, whereas with Predator armor, the beam can pierce at a relatively wide range of angles.
At multi-gigajoule yields, a lascannon would be vaporizing wide holes out of 350mm steel; I was under the impression these things had maybe a 10 cm beam diameter. Note that vaporizing a 350mm wide cylindrical "plug" of something with equivalent resistance to 350mm of steel armor is 2 gigajoules - i.e., similar to the upper range of the incidents quoted so far.
That's not a small hole in the side of a Land Raider, so I would suggest that's an upper limit for yield based on this particular set of data. Note it also matches the upper range of any lascannon incident thus far quoted in this thread.
A 10 cm wide plug vaporized, by contrast, would be only 164 MJ.
A hypersonic BT gauss rifle makes a modern kinetic penetrator look like blowgun darts. Modern main battle tank kinetic penetrators can threaten something with 350mm of conventional steel armor pretty well; by the descriptions of IA 2 cited above, a BT gauss rifle will blow through the armor of a WH40K Land Raider, Leman Russ, Predator, or other similar armored vehicle like paper.
Do we have anything else to benchmark WH40K armor vs kinetic penetrators? That's looking particularly bad at the moment.
Thanatos wrote:Besides we have numerous other events that show equivalent or greater firepower.
By all means, present them. The more evidence you present, the stronger your case.
Actually, the Lascannon is the superior weapon in universe. The rules take the Meltas cutting torch like operation into account but its in universe penetration and energy transfer is inferior to the Lascannon.
The rules
would appear to give Meltas superior effect against vehicles, within their shorter range... but I see nothing indicating lascannon energy yields exceed melta energy yields.
In fact, from the lack of excessive thermal fringe effects, we already have evidence
against lascannon achieving yields above and beyond the benchmarks.
There's no evidence of over penetration in the scene. Part of his chest gets vaporized and he staggers before collapsing.
Please do quote. I'd like to read the description for myself.
Bear in mind this produces numerous problems involving residual heat and the vaporization of human flesh. If it penetrates and vaporizes just the chest, then we have some extra problems, as only Space Marine bone is made of ceramite. Strongly variable yields make for overly complicated explanations or discarded evidence.
One thing I forgot to mention:
Roughly, for every 28mm of total suit thickness, you have ~0.1 cubic meters of suit, and I would be amazed to find that Space Marine armor was much more than a third the thickness of Land Raider armor.
You also need to take into account the fact that SMs have bonded ceramite rib plates (and ceramite bones in general. Their skulls are basically as good as the helmets they wear) acting as an internal layer of armor.
That will be worth doing once we have an actual incident, rather than a hypothetical case, of what a lascannon might be able to do to a Space Marine.
