ESP - Getting the students to teach

Today, the students taught each other about some specific engineering subject of their choice. Firstly, I took the students to the library and got them to choose a book related to their subject. The children's section in the library has many books which explain these concepts in easy English. The idea of this task was to get the students to talk about a subject that they already knew about in their own language, but needed to now explain it in English. Of course, like anything, it was difficult, but the students were starting to surround themselves with specialised vocabulary and concepts. It only took a little prodding from me to get them on the road to explain what they already knew about engineering, and at some times, quite advanced vocabulary. I then prized out what they needed to know and wrote some of the sentences up on the board and proceeded to give a grammar focus. Tomorrow, I intend to give the students more time to practise teaching the other students in their group about these concepts.
In all of this classroom task, the students are the ones who are developing their own knowledge and are in control of their learning in most parts. Hopefully, when the engineering teachers come in to actually teach the content, the students will already have been pretaught much of the content, but more importantly, engaged with the content in a way that they can manage.