Lechyfer asked me to do some Ork Battlewagon tactica, well hinted at it so here it is :)
Firstly looking at the Ork BW it's the strongest armour available to the Orks weighing it at 14 on the front and 12 on the side with a much lower 10 at the rear throw in it can hold 20 Orks makes this tank a pretty tough transport unit. As standard you'll notice it is open-topped, you can add a ard case upgrade to this but you shouldn't really do this in so many cases. Reason is having 20 Orks all shoot out from the tank while measuring from the hull is made of win, but secondly Orks can bail out of the BW and assault :) . While open topped is a benefit for the BW it's also a weakness. It gives +1 on the vehicle damage chart so a weapon say like a melta which gets 2D6 for armour penetration and also +1 on the vehicle damage chart making it +2 is a big enemy of Battlewagons and can stop them very easily.
The Battlewagon can be tooled up in a variety of builds such as a basic transport (which is my favourite) to a gun platform and smashing vehicles close up range.
If you're planning on making a Battlewagon a gun platform firstly consider it's poor ballistic skill which means you want a killkannon for template goodness or kannons or even lobbas too. Anything else you need to take in multiples i.e rokkits and you won't hit all that much. The problem with the gun platform is you're not using the Battlewagons transport ability which you're paying for, so you're wasting the tanks advantages. All in all I probably wouldn't go a gun platform as you need to stay put to fire all weapons and you need templates to avoid the low BS, plus you're not using the transport ability which you're paying for. However, if I did go gun platform I'd do something like this:
Battlewagon - killkannon, 'ard case & lobba.
The example above gives two templates and isn't open topped any more, after all you don't need it as nothing inside it, but this does cost a whooping 180 points and you could use the points on a far more better setup, in fact you can get 2 naked Battlewagons for that. In case you're wondering why I've put nothing else on it's because of the range and to avoid the Orky BS2. You could put big shootas on I guess which are the same range as a killkannon if I remember right ;)
What you could do is get a unit of 15 Lootas along with a Big Mek and throw them all in the Battlewagon. I'd take a KFF on the Big Mek for a nifty cover save bonus, but all this ends up costing a combinded total of 500 points invested in a single unit!! That's a lot of points in ont unit which is just about shooting and the Battlewagon can me made for better uses.
The transport Battlewagon or "Transwagon" as I've come to call it is about using the Battlewagon for what is does and that's carrying buckets of Orks to where they need to be. See the Wagon is better than a Trukk because it's better armour and carries more Orks; 12 Orks don't last 5 minutes even with bosspole and a armour 10 Trukk which is open-topped lasts even less. Ok the Wagon is over double points but it's a lot more strudy and you carry more Boyz, you pay for what you get ;)
Making a Transwagon is really easy. You need minimum a big shoota to asborb the weapon destroyed results or else you'll become immobilised, now for those who think of adding extra big shootas to take the results don't bother, because you can only move 6" and fire one weapon as it's S5. So don't waste the points. After the big shoota it's up to you what you put on, things to consider would be red paint job so you get there a little quicker, but, TBH it's only 1" so why waste the points? You could put grot riggers on to get your Wagon rolling again, but you need to roll a 4+ to get your Wagon moving which is 50/50 chance. What you should put on is a boarding plank as this allows one Ork (*hint the Nob with the power klaw!) attack a vehicle without jumping out the Battlewagon. This allows you to smash a vehicle without putting your Orks at risk and getting them shot to pieces next turn. What you could do as well is throw on a grabbing claw so if your boarding plank Nob does fail his duty then the enemy vehicle cannot drive off ;)
Battlewagon - big shoota, grabbing claw & boarding plank
The point of this Wagon is simple. Drive forward and shoot stuff from the safety of inside or roll up next to a enemy vehicle (providing they haven't move more than 12") and deploy the boarding plank and smash it. So that's armour destroyed and enemy infantry mauled all from the safety of your armour 14/12 Battlewagon :) . And, the bonus is you're using this for what it's for and not costing a packet like the Gunwagon.
As you can guess the Rollawagon is all about a dethrolla. Now I'll do another post about dethrollas as personaly I do not think they're all "that" but others seem to rave about them. What the dethrolla does best is ramming enemy vehicles and delivering D6 S10 hits which is going to auto glance most armour straight away, this can lead to a lot of wrecked enemy tanks. The good thing about the dethrolla is unlike a boarding plank you don't need to roll to hit, you just plough in and then roll your dice and see if you penetrated the armour of the enemy tank and then roll to hopefully destroy it, simples!
Seems the Rollawagon is about smashing enemy armour and moving as far as possible to ram enemy tanks red paint job is a must, but if you think you're not going to make it then some ranged fire power is required and I'd take the maximum amount of rokkits; you just cannot be sure with Orks.
Now two things to consider and one which is possibly answering the question on your puzzled face. Consider that when ploughing forward into that Imperial Guard Chimera what is exactly inside it, say some Veterans with 3 meltaguns isn't very nice for a Battlewagon and you're doing the Guards job by putting YOUR tank in THIER melta range, thanks buddy for that!
Next thing is a tactic and you're probably wondering why I'm taking 4 rokkits and a dethrolla. Consider that your Rollawagon destroys stuff up close, but what about if it cannot reach, kind of useless then isn't it or what about if it's immobilise as it won't be a threat then. Taking multiple rokkits allows you to take out a enemy transport if you're not in rolla range, hopefully you'll destroy it and then use the Shoota Boyz inside to lay down a salvo of fire on the survivors and hopefully you'll earn 2 kill points in one! :D
Firstly if you're going to take Battlewagons take them in multiples just like any unit. If you take just one people will know it carries a tough unit and will single it out. But when you've got multiples it just makes target priority and your army tougher in general. Also, when you do take them make sure you take them setup identically the same for the same reasons as above, you have just one dethrolla and it's already clobbered a vehicle already guess where all the anti tank is going? Yeah exactly, on the dethrolla Wagon.
When taking Wagons (or any Ork mech) a Big Mek with KFF is essential. When in a formation make sure the Big Mek's ride is in the centre so all vehicles are in 6" range to get the cover save bonus. Now you're vehicles are protected it's about keeping your Orks protected, move full steam ahead first turn with your Wagons and use supporting units i.e Lootas to pop enemy tanks. Next turn with mass Shoota Boyz roll up 6" and unleash 39 shots (if you have a Nob) of S4 fire power. People think Orks are all about assault which technically they are but they're crap at it, just listen why; they're S3 and only S4 when charged, they have low initiative and are fearless.
So if you do plan on assaulting make sure it's a small unit i.e Space Marines or a unit which isn't brilliant in combat i.e Imperial Guard or else you will get a mud hole stomped in you. Always stay in the Battlewagon against better close combat and bigger units and gun them down, use mutliple Ork units if you have to (you will thanks to BS2!) to do the job and then follow up with a multi assault if you wish, but remember you're putting your Boyz at risk so make sure nothing big and scary is close by i.e big blasts, flamers and better assault units.