Ron Heggs Posted March 22, 2012 Share Posted March 22, 2012 This build is a personal challenge, and in part a nod to George Stephenson who was born at Wylam in 1781 The bridge is 240ft in length, and in 4mm scale will be 960mm long, and construction will be in styrene - What else A quick CAD drawing - now no guessing how many cans it will support Link to post Share on other sites More sharing options...
RMweb Gold Worsdell forever Posted March 22, 2012 RMweb Gold Share Posted March 22, 2012 - now no guessing how many cans it will support But surely it will be bottles of 'broon ale'... Link to post Share on other sites More sharing options...
Ron Heggs Posted March 22, 2012 Author Share Posted March 22, 2012 But surely it will be bottles of 'broon ale'... Hi, Paul Not sure about stacking the bottles safely Ron Link to post Share on other sites More sharing options...
Fat Controller Posted March 23, 2012 Share Posted March 23, 2012 Our friends, Jan and Gordon, used to live at Hagg Bank in the 1980s- this bridge was the shortest cycling and walking route to Wylam from the hamlet, so we used to cross it quite often. Good luck with building it- I'll be interested to see how it turns out. Link to post Share on other sites More sharing options...
Ron Heggs Posted March 23, 2012 Author Share Posted March 23, 2012 Thanks Brian for your input A section through the bridge deck - 110.4mm overall width Link to post Share on other sites More sharing options...
Ron Heggs Posted March 23, 2012 Author Share Posted March 23, 2012 The deck bridge support beams completed - 20 x 110.4mm long x 9mm deep Link to post Share on other sites More sharing options...
scanman Posted March 24, 2012 Share Posted March 24, 2012 Uh oh - another masterclass in styrene-bashing! Think I'll go home now! Go for it Ron, looking forward to the finished model. Regs Ian Link to post Share on other sites More sharing options...
Ron Heggs Posted March 24, 2012 Author Share Posted March 24, 2012 Uh oh - another masterclass in styrene-bashing! Think I'll go home now! Go for it Ron, looking forward to the finished model. Regs Ian Hi, Ian Thanks for your motivating comments A scratchbuilding challenge is just what I need to keep my main long-running constructions on track - we all need alternative subjects to keep the tedium of main tasks from stalling The real challenge in this build is to ensure the bridge deck can be properly supported from the bridge arches by the relatively thin suspension hangers Cheers Ron Link to post Share on other sites More sharing options...
Ron Heggs Posted March 24, 2012 Author Share Posted March 24, 2012 20 of 22 deck support beams First six beams fixed to bottom flange of rail support beams All 22 beams fixed to bottom flanges Placed right way up Total length 966mm + 50mm at each end for deck support on stone built abutments at river banks Rail support beam webs and top flanges next - Link to post Share on other sites More sharing options...
Ron Heggs Posted March 24, 2012 Author Share Posted March 24, 2012 - a photo to show how flexible the construction is so far - Rail support beam webs and top flanges fitted - Full length shot - on same supports as first photo above The flexibility has almost gone Deck plating and its supports next - Link to post Share on other sites More sharing options...
N15class Posted March 25, 2012 Share Posted March 25, 2012 This is a nice looking project. The prototype is a spectacular bridge. I wish you all the best, what you have done looks very neat. Link to post Share on other sites More sharing options...
Ron Heggs Posted March 25, 2012 Author Share Posted March 25, 2012 This is a nice looking project. The prototype is a spectacular bridge. I wish you all the best, what you have done looks very neat. Hi, Thanks for your comments Ron Link to post Share on other sites More sharing options...
Ron Heggs Posted March 25, 2012 Author Share Posted March 25, 2012 Thanks to Paul, Wizard of the Moor & Scanman !! Link to post Share on other sites More sharing options...
Ron Heggs Posted March 25, 2012 Author Share Posted March 25, 2012 The decking side plating in place - - next the curved inter-rail plating Link to post Share on other sites More sharing options...
Guest Max Stafford Posted March 25, 2012 Share Posted March 25, 2012 Ron, your work rate is staggering! The deck's looking great too - this is almost an illustrated demonstration of how the full size article is constructed. Quite educational. Dave. Link to post Share on other sites More sharing options...
Ron Heggs Posted March 26, 2012 Author Share Posted March 26, 2012 Ron, your work rate is staggering! The deck's looking great too - this is almost an illustrated demonstration of how the full size article is constructed. Quite educational. Dave. Hi, Dave Thanks for your compliments - photos of the inter-rail curved plating will be posted tonight Cheers Ron Link to post Share on other sites More sharing options...
RMweb Gold Captain Kernow Posted March 26, 2012 RMweb Gold Share Posted March 26, 2012 Hagg Bank What a delightful name! Great work, as ever, Ron - the climate is certainly conducive to railway modelling! Link to post Share on other sites More sharing options...
Fat Controller Posted March 26, 2012 Share Posted March 26, 2012 The denizens of Hagg Bank (about 50 souls, mostly related apart from a handful of incomers like Jan and Gordon) used to claim that the bridge served as a prototype for two, somewhat larger, bridges of similar design- the Tyne Bridge and Sydney Harbour Bridge. I wonder if there is any truth in this? The entire settlement- about fifteen to twenty houses- appears to have been built to serve the railway; there was a junction between the Newcastle and Carlisle line and the line which ran via Newburn to Newcastle, along with extensive sidings on the Prudhoe side serving a chemical plant (Kimberly-Clark's plant is on this site) and a colliery. Link to post Share on other sites More sharing options...
Ron Heggs Posted March 26, 2012 Author Share Posted March 26, 2012 What a delightful name! Great work, as ever, Ron - the climate is certainly conducive to railway modelling! Thanks Just have to tear myself away from the villa reform, and lazing in the sun, to do a bit of modelling Ron Link to post Share on other sites More sharing options...
Ron Heggs Posted March 26, 2012 Author Share Posted March 26, 2012 The denizens of Hagg Bank (about 50 souls, mostly related apart from a handful of incomers like Jan and Gordon) used to claim that the bridge served as a prototype for two, somewhat larger, bridges of similar design- the Tyne Bridge and Sydney Harbour Bridge. I wonder if there is any truth in this? The entire settlement- about fifteen to twenty houses- appears to have been built to serve the railway; there was a junction between the Newcastle and Carlisle line and the line which ran via Newburn to Newcastle, along with extensive sidings on the Prudhoe side serving a chemical plant (Kimberly-Clark's plant is on this site) and a colliery. Thanks Brain I had heard about the bridge prototype story, and visited Kimberly Clark at Prudhoe a number of times during the 1970's & 80's on engineering projects Ron Link to post Share on other sites More sharing options...
Ron Heggs Posted March 26, 2012 Author Share Posted March 26, 2012 Thanks Andy Y, hope you will enjoy another plastic bending project Ron Link to post Share on other sites More sharing options...
Ron Heggs Posted March 26, 2012 Author Share Posted March 26, 2012 Thanks Captain K !! Link to post Share on other sites More sharing options...
Ron Heggs Posted March 26, 2012 Author Share Posted March 26, 2012 Only managed to fix one inter-rail curved plating section tonight - You may ask, why ? Was thinking about the deck support/hanger strength today, and having to prove their load limits before assembly Checking the clear space between the rows of support/hangers and also between adjacent support/hangers, shows dimensions of 52mm and 43mm respectively Test loads usually comprise cans which are 67mm diameter, and could not be accommodated The alternative is to test the support/hanger itself and the attachment methods A stress test for the bridge deck suspension support/hangers The bridge deck is suspended from 48 hangers – 16 per arch The hanger is made from 20thou x 100thou (0.5mm x 2.5mm) plastic strip The anchor pads fitted either side of each end of the hanger are also made from the same strip. The lower end being 14mm long, and the upper end 15mm long On the model the pads will be fixed to the ends of the deck support beams (contact area 9mm x 2.5mm), and the lower arch member (contact area 4mm x 2.5mm) For this test the pads are fixed to scrap 40thou pieces to enable the upper end of the hanger to be fixed to a suitable support, and also enable a test load to be suspended from the lower end The test is not only to test the ductile strength of the styrene, but also the shear strength of the fixing area of the pads Hanger with pads attached - the hole at the upper end is for the S hook - Upper end detail - Lower end detail - Test load - 2 x 440ml (2 x 0.4kg) Test - Result - No stretching of support/hanger No separation or distortion of pads or attachments Conclusion - The total load using the test load on each of 48 supports/hangers would be 0.8kg x 48 = 38.4kg (84.5 lbs) This is well in excess of any load expected to be placed on the bridge Link to post Share on other sites More sharing options...
Ron Heggs Posted March 28, 2012 Author Share Posted March 28, 2012 The second inter-rail curved plating completed - End views to show the curved plating - The deck centre plating can only be fixed when the middle of the three arches is completed with the support/hangers fixed to the deck beam Link to post Share on other sites More sharing options...
Ron Heggs Posted March 30, 2012 Author Share Posted March 30, 2012 The template for the three arches has been printed and fixed to the building board - - construction of the arches is about to commence Detail build process has still to be finalised - due to the numerous cross-bracings - Topside of lower arch/Both sides of top & bottom arches including the internal cross-bracings to the outer bracings - All in an arch cross-section just 10mm wide x 32mm high Link to post Share on other sites More sharing options...
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