With respect to Port & Rail, yes, it was originally an SDL project for many many years, but SDL signed 98% of it over to the Cameroonian government with the Transition Agreement in 2015.
Noteholders at the time were so desperate to get something, anything, back, they foolishly agreed to hand almost everything over.
Suggest you become familiar with the "Transition Agreement" and the agonising slow death history that followed.
You obviously need to play catch up with lots of research? (Rhetorical question)
Please do come back when you're better informed, and have something intelligent to add.