Thank you for your question! This is surely a unique case of tactile graphics! Fortunately, we have actual real-life examples to guide us.
I’d like to point you to the following story about Chris Downey, an architect who lost his vision and says he has become a better architect since! <https://www.hok.com/news/2019-01/chris-downey-an-architect-who-lost-his-sight-shares-his-story-on-60-minutes/>.
In this story you will see images of Mr. Downey reading raised-line drawings very similar to the engineering drawings you have shared in your message. These raised-line drawings are produced by a special industrial embosser on paper larger than the usual 11” x 11.5” paper used for braille documents.
With the likelihood you do not have resources to permit such large scale embossing, I will suggest that raised-line drawings of the type shown in the story linked above can be produced using hand-tooling methods on actual blueprints of the drawings. Spur wheels or clay-shaping tools could be used for this. I have even used flatware from the kitchen drawer, very dull pencils and hand-made implements with good effects! A rubber matt would make a good underlayment while making the embossing.
While the type of paper used to produce blueprints is not as heavy as used in usual braille embossing, it is much heavier than paper used for ink-print printing. (I can vouch from experience as I was once a draftsperson and made a living drawing architectural plans similar to what you show in your attachments.)
I suggest doing this using the actual blueprints at their full size because becoming facile at reading engineering drawings often requires that one is able to jump from section to section of the drawing while still keeping an overall orientation to the whole object(s) represented in the drawing. Cutting an “E-sized” drawing of the sort you display, into many smaller sheets would result in the students having to re-orient themselves to the parts and the whole every time they move to a different page. Trying to scale down the image so it fits on a smaller page would result in the lines being too close to each other for clear tactile reading.
Once the hand-tooled tactile images are produced, the paper can then be made a bit stronger and less prone to deforming, by spraying it with conventional artist’s fixative (be cautious that you do this outdoors and stand upwind of the spray, because the spray itself can be toxic).
I hope this helps. I’m eager to hear how these work for you and if you have more questions please come back!