Rich,
Looks good.....now You are doing some constructive thinking!
BTW: When You are ready to do the hoist platforms and are looking for pulley's (sheaves) Tichy just came out with some interesting ones that should work. Look for them in this link I'll post. Keep link for future use. The CMR bridge has 7/8'' size for referance:
https://www.tichytraingroup.com/WhatsNew.aspx
Take Care!
Frank
zstripe When You are ready to do the hoist platforms and are looking for pulley's (sheaves) Tichy just came out with some interesting ones that should work. Look for them in this link I'll post. Keep link for future use. The CMR bridge has 7/8'' size for referance: https://www.tichytraingroup.com/WhatsNew.aspx
When You are ready to do the hoist platforms and are looking for pulley's (sheaves) Tichy just came out with some interesting ones that should work. Look for them in this link I'll post. Keep link for future use. The CMR bridge has 7/8'' size for referance:
I have been collecting parts in anticipation of building the towers. Finding sheaves has been a problem. I have discovered Crow River Products which manufactures sheaves, so that is an alternative, but I really like the Tichy offerings.
Thanks again for the link.
Rich
Alton Junction
zstripe When You are ready to do the hoist platforms and are looking for pulley's (sheaves) Tichy just came out with some interesting ones that should work. The CMR bridge has 7/8'' size for referance
When You are ready to do the hoist platforms and are looking for pulley's (sheaves) Tichy just came out with some interesting ones that should work. The CMR bridge has 7/8'' size for referance
I know Wayne asked this once, but are you going to build the towers at the 47 degree angle, to the river?
I love old construction pictures. I don't see any copyright problems with this one.
Those are some huge sheaves.
Mike.
My You Tube
Trust Me again.....1'' would be fine for 8. Remember, that there are 4 cables for each set of sheaves, which consist of four sheaves in each set of 8. One sheave holds one cable. The sheaves closest to the main span, are the motorized ones, the ones holding the counter-weight are idlers for a 8 pulley system. That's going to add up in cost....so be prepared. The CMR bridge uses 3 cable sheaves and only 4 sets, no idler sets. The CMR used 0.032'' Teflon coated music wire for the cables. The teflon coating made it easier to glue to the sheaves,bridge,counter-weght.
PS: Finished one of the ship cranes yesterday.......what a challenge!
mbinsewi I know Wayne asked this once, but are you going to build the towers at the 47 degree angle, to the river?
On the prototype, the South Branch of the Chicago River runs on a soutwest-northeast angle, whereas the Pennsylvania Railroad tracks (double mainline) cross the river on a due north-south line. Not being an engineer, I am not sure why the bridge and towers were skewed, but they were in order to follow the banks of the river.
On my layout, I am designing the river and the bridge to run exactly perpendicular to each other. This does not trouble me because my layout does not exactly replicate the prototype. The layout closely simulates the prototype, but it is not an exact replica.
zstripe Rich, Trust Me again.....1'' would be fine for 8. Remember, that there are 4 cables for each set of sheaves, which consist of four sheaves in each set of 8. One sheave holds one cable. The sheaves closest to the main span, are the motorized ones, the ones holding the counter-weight are idlers for a 8 pulley system. That's going to add up in cost....so be prepared. The CMR bridge uses 3 cable sheaves and only 4 sets, no idler sets. The CMR used 0.032'' Teflon coated music wire for the cables. The teflon coating made it easier to glue to the sheaves,bridge,counter-weght. Frank
Although I am working in HO scale, I have to take into account that my entire vertical lift bridge project will be scaled smaller than the prototype equivalent.
For example, the prototype truss span would be 37.6245" in HO scale, but the bridge as I am kitbashing it will be 29.50". That translates to 78.4% of the prototype. So, a 2" sheave would scale down to a little more than a 1.5" diameter sheave. I will settle for 1" and purchase the Tichy sheaves.
zstripe PS: Finished one of the ship cranes yesterday.......what a challenge!
Glued the truss sides to the girder assembly. Ready to attach the lacings and the top bracings.
I'll answer Your other questions later.......But I want to point out.....Drill the holes in the end braces for the cables before attaching/gluing to ends......will make Your day so much easier. Also if You are going to run wires for power to a center shack, drill those holes now also, to accept a conduit for them, before adding any lattice bracing. I used 1/8'' brass tube.
Click on pic' for larger view and you can see the brass tube going through the deck girders.
zstripe Drill the holes in the end braces for the cables before attaching/gluing to ends......will make Your day so much easier. Also if You are going to run wires for power to a center shack, drill those holes now also, to accept a conduit for them, before adding any lattice bracing. I used 1/8'' brass tube.
Drill the holes in the end braces for the cables before attaching/gluing to ends......will make Your day so much easier. Also if You are going to run wires for power to a center shack, drill those holes now also, to accept a conduit for them, before adding any lattice bracing. I used 1/8'' brass tube.
Regarding the holes in the end braces for the cables, can you elaborate on that point a little more. I'm not sure that I understand your point.
richhotrainRegarding the holes in the end braces for the cables, can you elaborate on that point a little more. I'm not sure that I understand your point. Rich
Look at the top of the end of the bridge in the pic', there are three holes in the top end piece for the cables that lift the bridge. If You drilled them before gluing the end pieces on it will be easier to have both sides the same by using one as a template for the other side. Plus there will be less stress on them when pressing down on the bit to drill the holes. The holes in the CMR bridge were already in the end pieces:
zstripe richhotrain Regarding the holes in the end braces for the cables, can you elaborate on that point a little more. I'm not sure that I understand your point. Rich Rich, Look at the top of the end of the bridge in the pic', there are three holes in the top end piece for the cables that lift the bridge. If You drilled them before gluing the end pieces on it will be easier to have both sides the same by using one as a template for the other side. Plus there will be less stress on them when pressing down on the bit to drill the holes. The holes in the CMR bridge were already in the end pieces:
richhotrain Regarding the holes in the end braces for the cables, can you elaborate on that point a little more. I'm not sure that I understand your point. Rich
richhotrainSo, the ends of the bridge were not designed to be boxed but, rather, angled with an "end post" and X-braced struts across the top of the truss sides. So, I will need to fashion an end brace to provide a surface for the cable holders
That's exactly why I brought up the cable holes at this time......doing a little thinking ahead of You.....so to speak!
Frank, had you not mentioned it, I would not have thought about it until it was time to connect the cables. Since I am basically kitbashing multiple bridge kits, I have been following the general construction principles of the basic kit. The only trouble with that approach is that the basic kit is not designed as a vertical lift bridge, so it makes no provision for an end beam to hold the cable mounts.
Stay with me.
It would probably not be a bad idea, to wait until You get the Tichy parts and put four or three of the sheaves together, to see how far apart the holes would have to be in the top of the bridge ends, so they will all be uniform and perpendicular to one another, which is a must. Once together, they would stick out like a sore thumb, if they were not.
zstripe Rich, It would probably not be a bad idea, to wait until You get the Tichy parts and put four or three of the sheaves together, to see how far apart the holes would have to be in the top of the bridge ends, so they will all be uniform and perpendicular to one another, which is a must. Once together, they would stick out like a sore thumb, if they were not. Take Care! Frank
On the CMR vertical lift bridge that you built, which is significantly different from the PRR vertical lift bridge that I am building, there are 2 angled towers, supporting 4 sheaves with each sheave supporting 3 cables, or a total of 12 cables. This arrangement is true to the prototype.
There was a similar angled tower lift bridge in Chicago at Halsted Street for many years, although it had 4 cables per sheave, or a total of 16 cables.
The PRR vertical lift bridge in downtown Chicago has 2 towers with 4 sheaves on each tower, or a total of 8 sheaves. Each sheave supports 16 cables, or a total of 32 cables per tower, for a grand total of 64 cables.
So, for me, the issue becomes one of selective compression. How many sheaves do I install and how many cables per sheave do I install? The minimum, of course, would be 2 sheaves, one per tower, or a total of 4 sheaves. However, it would be much more realistic to install at least 4 sheaves per tower, or a total of 8 sheaves. As far as cables are concerned, if I limited the number of cables to 1 per sheave, that would require 8 cables. So, in my mind, I ask myself, where do I start and where do I stop?
I really do like the Tichy sheaves, but they are designed to hold a single cable per sheave. On the prototype, each sheave is wide enough with sufficient grooves to support multiple cables. Your CMR sheave is a good example. A single sheave has 3 grooves to support 3 cables.
So, I am struggling with this aspect of the project. How many sheaves and how many cables?
Well to be honest, yet realistic, I believe a minimum of three cables per sheave would be realistic. Those Tichy ones should be able to be butted together, that is how the CMR ones are designed. I actually added one to the outside of an outside one so the spacing was eliminated at the top of the hoist platform. Meaning....they wanted you to put seven halfs together to form one set. But when you did that, there was a gap between the end sheave and the mount......I did not like the gap so I added an end to one side of each set.
If You look at the pic' and count starting from the left, You will see what I am talking about. The unpainted parts were scratchbuilt by Me and the brass shaft was inserted into the sheaves into the end brace. They were also designed to keep the shacks in alignment and stop light bleed through the edges. The holes in the kit sheaves are square so they all line up exactly the same.......but... a square part will not fit into the round holes of the gearing I used, so I used brass 1/16'' rod for the shafts and only used the square shafts supplied to keep the sheaves all the same while the adhesive dried.......worked fine!
Frank, these last pictures you've shown, I think, are the first pictures I've seen of the completed bridge, with ladders and railings, and buildings in place.
Excellent!
I can't wait to get a glimpse of that ship!
Mike,
Thanks for the comments. I'm pretty sure those photos were in one of My last posts in that thread. I did not post a final picture of the different color ties, because the bridge is at the Grandkids house layout so I could set-up and lay the track to it.......that is why I built it, for them......I have enough bridges on what's left of My layout.
If no one complains.......how about a sneak peek!
British Battleship HMS Prince of Wales.
The deck is real laminated wood:
zstripe Rich, Well to be honest, yet realistic, I believe a minimum of three cables per sheave would be realistic. Those Tichy ones should be able to be butted together, that is how the CMR ones are designed. I actually added one to the outside of an outside one so the spacing was eliminated at the top of the hoist platform. Meaning....they wanted you to put seven halfs together to form one set. But when you did that, there was a gap between the end sheave and the mount......I did not like the gap so I added an end to one side of each set. If You look at the pic' and count starting from the left, You will see what I am talking about. The unpainted parts were scratchbuilt by Me and the brass shaft was inserted into the sheaves into the end brace. They were also designed to keep the shacks in alignment and stop light bleed through the edges. The holes in the kit sheaves are square so they all line up exactly the same.......but... a square part will not fit into the round holes of the gearing I used, so I used brass 1/16'' rod for the shafts and only used the square shafts supplied to keep the sheaves all the same while the adhesive dried.......worked fine!
I have determined though the the towers should be 5" x 6" so that will have some decided effect on the size of the sheaves and the number of cables. One other consideration to take into account is the fact that the four sheaves on each tower do not sit on a single platform. The "platform" at the top of each tower is actually a set of four girders. The left side sheaves sit on one girder and the right side sheaves sit on a separate, parallel girder, so space is limited.
The CMR bridge main span is 4 3/4'' wide. The hoist platform is 5'' wide x 1 1/2'' and it holds the 16pieces for the sheaves, the motors, gears and the shack, along with a three sided railing. So if You were to make yours 5'' wide and 4'' long, you would have more than enough room to put anything You want up there. Remember...part of the sheaves overhang the edge on both sides so the cables do not rub on the structure. Look at the pic', you can see how they overhang. The four sets on Your bridge should do the same.
I'm sure there must be at least a partial floor on the hoist platforms.......it would be awful dangerous to do any maintenance on moving parts, if you just had girders to walk around on.
Don't start over thinking.........
EDIT: This pic' should give You a better shot of the sheave overhang:
They can be clicked on for a larger view.
zstripe Rich, The CMR bridge main span is 4 3/4'' wide. The hoist platform is 5'' wide x 1 1/2'' and it holds the 16pieces for the sheaves, the motors, gears and the shack, along with a three sided railing. So if You were to make yours 5'' wide and 4'' long, you would have more than enough room to put anything You want up there. Remember...part of the sheaves overhang the edge on both sides so the cables do not rub on the structure.
The CMR bridge main span is 4 3/4'' wide. The hoist platform is 5'' wide x 1 1/2'' and it holds the 16pieces for the sheaves, the motors, gears and the shack, along with a three sided railing. So if You were to make yours 5'' wide and 4'' long, you would have more than enough room to put anything You want up there. Remember...part of the sheaves overhang the edge on both sides so the cables do not rub on the structure.
zstripe I'm sure there must be at least a partial floor on the hoist platforms.......it would be awful dangerous to do any maintenance on moving parts, if you just had girders to walk around on.
zstripe One sheave holds one cable. The sheaves closest to the main span, are the motorized ones, the ones holding the counter-weight are idlers for a 8 pulley system. That's going to add up in cost....so be prepared.
One sheave holds one cable. The sheaves closest to the main span, are the motorized ones, the ones holding the counter-weight are idlers for a 8 pulley system. That's going to add up in cost....so be prepared.
I am concerned about space limitations up at the top of the towers, and cost becomes an issue as well. Those sheaves are $3.50 a pair, so if I wind up installing 4 cables on each sheave, that would require 16 pairs of sheaves for a total cost of $56.00. That seems excessive just to complete the sheave portion of the project. I have considered scratchbuilding the sheaves to save money. One thought that I have had is to fabricate the sheaves out of thin wall plastic pipe. Thoughts?
If cost is Your concern, take a look at this Plastruct link and on page 37 for Handwheels/Disc's. You could make Your own sheaves with a spoke on the outside and disc. in the middle, followed by another spoke and so on. Should be a lot cheaper than the Tichy parts. And No.....I would not try to make them out of thin styrene, not when there are offerings already out there. Cutting a round disc from sheet styrene is pretty hard to do and cutting from a tube isn't so easy either.
http://www.plastruct.com/catalog/Vol_10_CatalogSMFL.pdf
Edit: While You are on the Plastruct site, look at the gussets. They have no rivet detail, but are at least already cut to size. Page 18
richhotrainThose sheaves are $3.50 a pair, so if I wind up installing 4 cables on each sheave, that would require 16 pairs of sheaves for a total cost of $56.00.
I came across these neat-looking gears, cogs & wheels a while back at Amazon, maybe others:
https://tinyurl.com/yypny39j
There's a dozen or more designs in each bag and maybe six or eight of each design. Maybe these could be a starting point for your sheaves?
cog_2 by Edmund, on Flickr
If you found a thin-wall corrugated tubing, then stuffed it with these gear hubs, maybe with the teeth sanded off you might get a neat looking assembly. Or you could wrap them with grooved styrene sheet cut into a strip. Put the joint at the bottom, out of view.
cog_3 by Edmund, on Flickr
These that I stuck onto a nail are five HO feet in diameter:
cog_4 by Edmund, on Flickr
IMHO, the Tichy and the old SS Ltd "Mine Head" sheaves are too spindly looking to support the massive weight of a lift-bridge.
cog_ss-ltd by Edmund, on Flickr
The two on the left might work but, if you can find them, they are about double the cost of the Tichy ones. It is too bad the old Life-Like gears are so large (ten-feet in HO) as I believe the spoke pattern is perfect for a lift bridge, although, the big old NYC RR bridge at the mouth of the Cuyahoga River here in Cleveland has sheaves that are at least that size. (NJ, too, see below).
Cog-Life-Like by Edmund, on Flickr
Here's a look at the Newark Bay Lift Bridge on the C. RR of N.J.
NJ_bridge by Edmund, on Flickr
Looks like there are guards over the tops of the sheaves so you really don't see the cables or grooves. But it would be a nice detail to see them on a model.
NJ_bridge-sheave by Edmund, on Flickr
Hope that helps—
Good Luck, Ed
Frank and Ed thanks for those suggestions and links. More to think about.
I came across this item from Preiser, a cable drum set of 4 which looks pretty cool, but I cannot find dimensions like diameter and width.
https://www.preiserusa.com/Preiser-17117-Cable-drums-and-crates-Kit
zstripe Edit: While You are on the Plastruct site, look at the gussets. They have no rivet detail, but are at least already cut to size.
Edit: While You are on the Plastruct site, look at the gussets. They have no rivet detail, but are at least already cut to size.
Yesterday, I finished installing the top and bottom lacings. Today, I will finish the top x-bracing, and that will nearly complete the bridge except for some minor finishing touches.
Looking great Rich. So much sheave info! Who knew?
mbinsewiLooking great Rich. So much sheave info! Who knew?
Yes, excellent model, Rich!
There is some additional counterweights and sheaves to support the power cables which might make for a neat detail if you're ambitious enough
NJ_bridge-power by Edmund, on Flickr
I remember being at Bridge One in the Cleveland Flats one July Fourth. I was friends with the operator. He gave us a ride to the top of the towers to watch the fireworks at nearby Edgewater Park!
That was some times to remember! Below is a look at the present-day "Bridge One"
1028181411 by Edmund, on Flickr
Cheers, Ed