19 replies to this topic

[Dfenz]

Twin Iron train bridge designed to carry tracks over gaps at tables at exhibitions


Iron train bridges by Dfenz, on Flickr

I am aware that other people have used similar trapezoid parts ( http://www.bricklink...tem.asp?P=55767 ) for train bridges. This is something I'd planned a few years ago and I was fortunate enough to acquire around 30 of these pieces back then for much lower cost (and from one store) than would be the case today. Its only last weekend that I actually put the pieces into the use they were purchased for. Incidentally those particular pieces can be combined in different ways to make a large roof structure, e.g. for sheds or train stations, if they are turned upside down and rotated about 45 degrees to rest on the angled edge.

[lightningtiger]

I like it 'Dfenz'....great work, reminds me of the bridge at Murray Bridge, South Australia.

[JopieK]

Very nice work indeed! Especially the twin version!

[asleepatheswitch]

Excellent!  Looks great I want it!!

[LEGO Guy Bri]

Sitting on a gold gray mine with so many of those girder pieces! That looks awesome! What length can is span safely?  

[LegoSjaak]

The first time a saw these pieces, i wasn't really enthusiastic... they were not very lego-ish like the nose of the 7897 ICE train...but now that i got some of the pieces....it is nice to make a bridge of it... I did the same thing a few months ago...







Greetz, LegoSjaak

[Piranha]

Very nice bridge Dfenz, those parts are indeed useful for making bridges. I plan on making a similar one for my layout. What is the recommended method to incline track at though?

[LEGO Train 12 Volts]

This twin version looks really great!  

[1974]

Looks great Those elements were made for that purpose only. Thanks TLG!  

[JamesP]

1974, on 13 April 2012 - 10:41 PM, said:

Looks great Those elements were made for that purpose only. Thanks TLG!  

There's an even better Lego element than that for making bridges:



Talk about perfect for bridges.  It will cross 5 track length gaps at least, that's about all I have of them.

James

[The Blue Brick]

JamesP, on 14 April 2012 - 04:39 AM, said:

There's an even better Lego element than that for making bridges:



Talk about perfect for bridges.  It will cross 5 track length gaps at least, that's about all I have of them.

James

What piece is that? I'm not much of a technic guy.

[JamesP]

The Blue Brick, on 15 April 2012 - 01:19 AM, said:

What piece is that? I'm not much of a technic guy.

If you property the image, then cut the number & post it into bricklink (that hosts the image), you would have gotten to:

http://www.bricklink...tem.asp?P=32213

Znap, rather than Technic.

James

[JopieK]

but they are quite rare! old fashioned tech beams with studs also work very well!

[Richie]

Macoco, on 10 April 2012 - 11:10 PM, said:

What is the recommended method to incline track at though?

Try this topic.  

[The Joker1]

Nice work. That looks like one strong bridge. Do you know what sort of weight it can hold?

[JamesP]

JopieK, on 15 April 2012 - 10:39 AM, said:

but they are quite rare! old fashioned tech beams with studs also work very well!

Really?


DSC00169 by Peach James, on Flickr

I'd have never guessed...

(26 sections/11 ft or so long, yes it will self support a 3.5 kg train crossing, but it tends to bend excessively in the centre when I have run it without its centre post)

James

[broomhandle]

JamesP, on 16 April 2012 - 02:58 AM, said:

Really?


DSC00169 by Peach James, on Flickr

I'd have never guessed...

(26 sections/11 ft or so long, yes it will self support a 3.5 kg train crossing, but it tends to bend excessively in the centre when I have run it without its centre post)

James

holy crap. any better photos of that?

i cant believe a train can cross that. is that support beams under it?

way cool!!!!!



i love the bridge in the 1st post, just those pieces are so rare and expensive. :(

[JamesP]

broomhandle, on 27 April 2012 - 12:13 AM, said:

holy crap. any better photos of that?

i cant believe a train can cross that. is that support beams under it?

way cool!!!!!

OK, so some more photos of the large bridge:

To answer questions, it will self support up to at least 3.5 kg.  However, the flex in the middle is quite shocking when doing so, and the amount of hill the train has to climb is rather excessive.  So, by adding the post in the middle, the forces involved are reduced to 1/4th, and the bridge is far more stable.  Since version 2 suffered a failure, I was a bit reluctant to test with the full Santa Fe.  Instead, I started with a heavily containered train, until I had run rather more weight than the full (6 car/3 engine) Sante Fe was across the bridge without the support pillar.  I then ran the Santa Fe across the bridge, without the support pillar, and came to the conclusion that I wasn't that comfortable with the bridge as I had designed it.  I am aware that there are some issues with how I built the bridge- the top beam should be the thicker chord, not the bottom one.  It is a pre-stressed design, that's what the cables within the bridge are used for.  (they compress the bridge, to take some of the flex out of the structure)




Version 1, suspension bridge

Old Lego bridge by Peach James, on Flickr

One of these days, I will rebuild the bridge again.  But, since it is workable, there is no pressing need.  The yellow end support structures are full of Pennies (perhaps that's why Harper is getting rid of them???) that I am using as ballast to keep them in position.  

James

[funkdis]

JamesP, on 27 April 2012 - 05:32 PM, said:

OK, so some more photos of the large bridge:


Version 1, suspension bridge

Old Lego bridge by Peach James, on Flickr

One of these days, I will rebuild the bridge again.  But, since it is workable, there is no pressing need.  The yellow end support structures are full of Pennies (perhaps that's why Harper is getting rid of them???) that I am using as ballast to keep them in position.  

Suspension bridge is held with fishing line? because I cannot see anything

[LEGO Train 12 Volts]

Wow this is crazy!