I have a lucky job, in which I some times have to visit a food processing plant. (Proscess equipement desinger & installer)
I have seen teh inside of 'Blue Water Seafood' who make teh classic fish sticks, among other tasty fish treats..
Fish Sticks start aout as a 20kg block of prepared frozen fish fillets. These blocks are about 20x12x4 inches. The blocks are broken donw to manageble 'slabs' (20x4x1) thought a series of band saws.. yes, band saws.. and conveyor systems. These slabs are then put into a machine which chops them into 'fish sticks. Thsi machine, probably has about 15 'slots' for said 'slabs' Chunk! Chuck! Chuyck! the machine goes, dropping them sticks onto a mesh conveyor. Periodic checks to ensure teh sticks are neither too heavy or too light. Then they are dipped itot eh batter. Then intot eh deep fryer. This fryer is about 20' long, and about 5' wide. Covered of course, and vented. Then they emerge, afteter a pre=set cook time (the speed of teh conveyor x distance = total cook time)
then they go into a giang freezer, in which teh conveyor continues at its pace for about another 5 or 10 minutes to 'cool & freeze' teh fingers. they then are dumped into a 'pool, which is surrounded by about 10 women who grab the right amount per box, and place them in the box. The box is sealed, then placed in teh shipoping box, which alsoi then seqaled. Then, back int eh freezer they go! the whol process probably takes about 30 minutes.
The two weeks I was there, working with the QC / QA people, I ate enough fish to, well, I had fish fillets & patties & sticks every lunch time! Fries too!!
Smell? No, teh fish is moslty frozen, so it dosen't smell. The oil cookers smell more than anything. Everything has to be able to withstand their 'washdonw cycle, which happens every few hours. Line up the machines, open them up, and spray them down with fire hoses...
I've seen Dog food, peanut butter, chocolate bars (Hershey's & Comet), coffee, bread, concrete ( ready mix & pre-cast) being made. Neat, but can turn your stomach..