Are stair bulkhead timbers in any way loadbearing?

[SADOLDDEEJAY]

There are three short lengths of timber that come into the floor of a room over some stairs, at an angle of roughly 30 degrees. As far as I can tell, their only function is that they support a short length of plasterboard over the stairs. The timbers currently are boxed in and have a shower tray fitted above them and mean that it's quite a step up to get into the shower. I'm wondering if I'd be safe to cut a significant notch into the timbers to allow me to lower the platform that supports the shower tray? The plasterboard weighs very little. I'm thinking if necessary strengthen the timbers with some thin steel brackets if necessary. (Hope the preceding text makes sense.)

 

[tony1851]

Pics needed here.

 

[SADOLDDEEJAY]

The description is from memory from when I installed the shower tray about 15 years ago. When I've removed it next week I'll take some pics.