Fastest speed around Hornby 3rd and 4th radius?

[sub39h]

Hi guys, 

 

For what seems like the umpteenth time I am in the process of designing a layout. I think I've finally found a way to fit in almost everything I want in the space I currently have available. 

 

The branchline approach to my main station is being designed to give the illusion that it is coming from somewhere else, so were the mainline approaches in a curved fasion in plain view, the branch line goes straight towards the wall and will disappear into a tunnel, where it will have to make a sharp turn. This is where I will use the 3rd and 4th radius curves. 

 

Because the branch line has access to some of the through platforms after which it joins the main line, I want non-stop trains to approach at main line speeds. Is this likely to be possible? I don't want to have too many issues with derailment because I plan on using a sort of open framework for that area to give me access if something derails in the tunnel in that area, but it will still be fairly awkward to get to. 

 

TIA

[34theletterbetweenB&D]

Unless the centre of gravity of the stock is unduly high - and that can be corrected in most cases with judiciously applied low down lead - a scale 150mph is possible on set track, and some stock will go yet faster before toppling off. It is the running reliability of really belting stuff that is more of a problem. Carefully laid track with no 'bumps' at the joins, care over pick ups so that power supply is continuous for no jerks from the traction, smooth acting bogies and couplers, modest train length, are significant factors.

 

All that said, a good many years ago now I created a high speed train using the original Bach Peak chassis at both ends, with return loops of 3rd radius. On the straight lightning acceleration to a scale 400mph was possible, the return curves were taken at just under 200. This ran very well until a couple of track pieces on a curve which had not been tacked down moved enough to disconnect.

[Pete 75C]

I think in all honesty, you won't know what's possible until you try it. There is a point where you will know what approach speed looks good and what looks unrealistic for the curve. My old Hornby Duchess used to enter the platform on my chipboard oval at a ridiculous scale speed probably approaching 200mph. It looked great but I was 7! I find scale speeds a little odd in that a realistic main line scale speed of 75 can look good but walking pace yard shunting can look too slow.

Pete.

[sub39h]

Thanks for the replies so far. I may have been misunderstood - the 3rd and 4th radius curves will be out of view so it's not about what looks good but rather whether non-stop trains can enter the station and high speeds to join the main line. To be honest I may have other problems as the train has to negotiate a sort of S bend through point work to get onto the right track to do this so I might need a rethink anyway

[Flying Pig]

It's likely that there would have been a speed restriction through the junction for branch trains in real life, particularly if it involved a reverse curve.  That's not to stop you running at Battle Space speeds if you want, but you have a good excuse not to if it's inconvenient

[sub39h]

that is a fair point. i had expected as much, which is why i am thinking about changing the station layout so that the branch line is more straight. i don't have access to my track plan at present but to explain the branch line when going straight on has 2 terminus tracks, so instead it banks around them onto two through platforms, and one of those lines can also be used to terminate and switch direction for bi-directional trains such as local DMUs.

 

i could make it so the terminus platforms straight on become the through platforms, and the other two in between that and the main line become the terminus platforms so that the approach speed can be higher, but i like the fact that the terminus platforms will be up against a wall, and i was planning on putting my main station building there.

 

in regards to chosen speed, i'm not just going for absolute maximum, but as i'm interested in express trains and most of my trains will be 100mph+ i want at least some of them to be at near full speed through the station. the main line has two through roads between the two platforms for non-stop trains, but it would be nice to see quick trains from the branch line join the main line as well.