There are lots of leaked images out on the new Imperial Knight codex release, and I am not sure I had anything pointing towards the "Tripartite Lance". Regardless here is a chance to check them out, and at the very least a chance to check out the new Imperial Knight Warden Sprues!
Here are some links over to Gamestrust who seem to be on top of the latest images. They are in German.
Knight rules and formations (including "Tripartite Lance"):
It shows the Imperial Knight Warden kit, bits etc.