Wow indeed!. Those are impressive Steven, good job you had the camera close to hand to capture those. As for what they are...I simply don't know!. The white mid level cloud is a type of altocumulus, the dark lower cloud is either cumulus or broken stratocumulus, I suspect the curved formation could be some sort of accessory cloud under the cumulus perhaps drawn into a curve by a local area of vorticity or convergence zone but I'm blindly guessing.
Bit of a tricky one. Brian, any ideas?.
Nice catch anyway!
Here's a couple of convective maps for today. Both these show broad areas of vorticity over N. Ireland today so this might have caused that effect.