Multiple networks over 3 locations

[3clipse]

Good Morning All,

I am quite new to PFSense, and have been tasked with setting up a static route between a few sites.

We have 3 sites, with IPSec tunnels from A-B, and B-C.

A = 10.10.0.0/23
B = 192.168.3.0/24
C = 12.0.0.0/11

I need to set it up so A and C can communicate but go through B.
i.e. 10.10.1.58 (my machine) -> 10.10.1.1 -> 192.168.3.1 -> 12.0.0.1 -> 12.0.0.4

I have read that standard static routes won't work through IPSec tunnels, and that I need to configure the remote networks in the IPSec settings, but when i add the 12.0.0.0/11 remote network to the 192.168.3.0 tunnel, it doesn't work.
A traceroute just shows the packet stopping at my firewall and not going anywhere else.

Could anyone please explain how I need to set this up?

Many thanks,
Logan.