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Block Behavior

Dan?

Roller Poster
How, in the real world, do blocks work? Obviously there's the whole "controlled stop-point" thing, where a block is theoretically delineated by where a train can safely be brought to a stop, but real coasters are much more nuanced than just that - whether it be accelerators with their high-point prox switch, or B&Ms with their combined-but-not-the-same service & safety blocks.
I'm particularly curious about smaller, early-to-mid 90s B&M inverts. I've read somewhere that the way they behave prevents a train from being dispatched from the station until the next two blocks are empty - both the lift and the service brakes, and I'm also not entirely sure about what happens in regards to lift creep on these older models. I've heard Dragons introduced lift creep to B&Ms, however I don't have any reliable means of backing this up.
 

Indy

Hyper Poster
There's a lot to unpack here and I'm not entirely sure what you mean by some of it, but I'll try my best to explain what I can.

First, with a few exceptions, it is generally very simple. There always needs to be a block brake between one train and the next. That way, if something happens where train A doesn't complete the circuit, then there is still a block in between train A and train B that can safely bring train B to a stop and avoid a collision. So, the controls program will keep track of when a train has passed through a block. If train A hasn't reached/cleared a block at the time train B is in the block behind it, then the program will trigger the brakes in that block to stop train B.

...or B&Ms with their combined-but-not-the-same service & safety blocks.
A lot of the B&M inverts have excessively long brake runs that obviously include maintenance areas. A block only needs to be as long as the space required to safely stop a train. So, when you enter the brake run, the space needed to stop the train can be one block. After that point, the track can be broken into blocks based on the length of the train, so it's possible to create a series of blocks in the same straight length of track and stack all of the trains.

I'm particularly curious about smaller, early-to-mid 90s B&M inverts. I've read somewhere that the way they behave prevents a train from being dispatched from the station until the next two blocks are empty - both the lift and the service brakes...
I'm not sure if that's true, but if it is, then that is strictly a safety preference by B&M and/or the controls engineers they used.

and I'm also not entirely sure about what happens in regards to lift creep on these older models. I've heard Dragons introduced lift creep to B&Ms, however I don't have any reliable means of backing this up.
Do you mean how the lift hill starts out slow with a train on it and then speeds up while a train is on it? Obviously, Dragons featured that for the sake of trying to line up interaction points between the two trains. I can't verify if that was B&M's first use of it. On more standard applications, the concept is that the lift hill is obviously a super long block and the train will only reach the end via the lift itself. So, you can dispatch a train onto the lift theoretically before the block after the lift hill has been cleared. It's advantageous to run the lift motor slowly to give the train ahead more time to get through the block. Once the train ahead clears the block, then you're good to go and the lift motor cranks up to its normal speed. And if the block never clears, then the lift will shut off completely once the train reaches the prox sensor at the top of the lift.

I hope this is of some help and answers your questions. My apologies if its too confusing or too simple. I'm happy to try and answer any subsequent questions you might have.
 

Dan?

Roller Poster
Do you mean how the lift hill starts out slow with a train on it and then speeds up while a train is on it?
Yes - Galactica is quite an infamous example, where it starts out at its engage speed, then once the train is on the straight it slows to idle to allow the train ahead to proceed off the brake run before speeding up to normal pace. I'm aware of why and when a lift creeps, I'm just curious about if it was ever on any models before Dragons, and if not, whether the dispatch inhibit is/was a real thing.
 

VonRolland

Hyper Poster
Inverts don't require 2 blocks to be free in order to dispatch they can dispatch while the other train is mid way round as long as the train in front has reached a fixed point known as a Dispatch Interval as for lift speeds on older Inverts there are techinally 2 speeds however there is a slightly slower speed for when the train infront hasn't hit or cleared Service (It's very hard to spot tho)

Galactica starts off at full lift speed to ensure the craft has engaged fully on the lift before slowly to a creep
 

Dan?

Roller Poster
Galactica starts off at full lift speed
I thought Flyers had a 3-speed lift, where the lift starts off at a slightly lower pace than normal, because of the sheer weight of the crafts.

I've had an insider tell me that Nemesis actually stacks at the bottom of the lift if Service isn't clear, and will stack again up at the lift top if Safety isn't clear too (though in practice it never does!) What up with that?
 

VonRolland

Hyper Poster
I thought Flyers had a 3-speed lift, where the lift starts off at a slightly lower pace than normal, because of the sheer weight of the crafts.

I've had an insider tell me that Nemesis actually stacks at the bottom of the lift if Service isn't clear, and will stack again up at the lift top if Safety isn't clear too (though in practice it never does!) What up with that?
Lift Idle (no crafts), Full Speed & Craft Idle. The lift can start at full speed because the feeder wheels at the base are ever so slightly faster than the lift so the craft is gently placed on the lift.

Nemesis never ever stacks at the base. If safety isn't clear by the time its about to crest it will stop at the top but if the train in front has stopped in transfer it'll crest
 
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