Thank you all, I just passed it 
Ok i get it. i couldn’t jump it so i thought i wasn’t suppose to go that way on the bottom level. OK thanks guys. (just hug the wall and walk it)
Or use explosives to lure it away
Ill be quite honest… This game is quite scary during these industrial areas. Im stuck in silo 8 near the giant fan. What can i do? Im quite nervous to go down near the fan.
Fan isn’t running so you will have to go and trun it on (there are no monsters there), when you trun it on watch out how you are climbing the ladders because the fan can kill you. Then just jump and the fan will make you fly and you should go in some of the shafts.
After defeating the first Tentacle monster in the silo, I go down the ladder and fall into the pool of water where it’s remains are but the only door won’t open. Help on what to do?
Pool of water in the middle of the room, jump in, then swim down and then up.
thanks a lot
Not sure I understand 
the pit where the tentacle monster was. Go down it. you are now in a pool of water. Swim “outwards” (it is a big circle, swim towards the edge) and then up. You should be in a new room
MS paint
best paint
I got stuck here for quite a while but stuck with it and kept going down to look for openings, then back up for air… Eventually found it.
I’ve found i’ve tried things for longer on BM than other games. Other games I give up quickly and look it up but i’ve found with BM most times things are logical and eventually you’l figure it out… Just requires patience and thinking
Have done this level loads of times with vanilla HL but I get killed very quickly by the pit monster in Black Mesa.
Firstly, the walk key isn’t functioning and I’ve tried mapping to many different keys so I’m trying to do this by crouching.
Secondly simply throwing a grenade draws attention and gordon is killed straight away. Also stepping onto a ladder or off if I get that far does the same.
It all seems a buit over sensitive!
Turn off auto-run.
Throw grenade, run like hell.
That’s how I’ve always done it and it always works, even i Black Mesa.
Get through the first door, and finish that section, then you can jump down from inside so you don’t have to go by the monsters in order to get to the lowest level.
Think, run, shoot, live 
^ this
Everything idicates “ready” but the fire button for the missile is red and wont do anything. Am I just being a derp?
Have you loaded the fuel and powered up the generator?
Im not best at explaining things so just bear with me.
If you are hundred percent sure you turned all the powers,
you have to go back to the room where a scientist got killed by that tentacle through the window. Judging by the statement, “the fire button for the missile is red” i assume you know where that is. Then you have to press “E” to launch, then huge explosion kills that monster.
If nothing happens, i would make sure you turned all the powers.