किसी किसी ब्रिज पर ट्रेन की रफ़्तार धीमी क्यों कर दी जाती है? 

True bro

@@sunnyyy.__3948 I willing and x x I willing to help you with that I willing to take

*on

Bullet train runs at 350kmph on both bridges and land

E

Zzdc nm

A

I also think so.

Farakka Barrage is a bit of an unfair comparison. It is not only a bridge, but also serves as a barrage holding back water (the struts are shared between the bridge and the dam), so to prevent overstressing the dam, the trains are slowed down. The main discussion is a lot more nuanced, having answers in structural engineering and geography. 1. If the bridge is a truss bridge with the spans of the trusses being short, then it can handle high loads and high speeds, and vice versa. Same goes even for concrete bridges as well. 2. Another key component that many people overlook in these comparisons is the foundation beneath the pillars. If there is a solid bedrock beneath the riverbed silt, the engineers can firmly anchor the pillars to the bedrock, which makes the bridge much more stronger and capable of handling high speeds. Otherwise (for clay based foundations), the engineers are forced to use unconventional solutions such as spreading out the base of the piers and using pile struts to stabilize the soil, which limit the operational speeds compared to foundations on solid bedrocks. 3. Another technological improvement in the recent times (late 2000s), is that concrete formulas have gotten much more stronger by the late 2000s than concrete formulas pre 2000. This, combined with cheaper and more versatile concrete pumping assemblies mean that constructing beams and structures of bridges with concrete gives a much stronger, yet economically viable bridge, comparing to fabricating the parts out of steel. Thus, modern day bridges are mostly concrete bridges, unless the gap between pillars is too long to get a concrete beam in between. 4. Even the gap between the pillars cannot be arbitrarily fixed, and needs to take into account the local boat traffic or geography, depending on the place. This reduces the options of bridge designs in many places. 5. Lastly, the age of the bridge also plays a key factor. As a bridge ages and more traffic passes over it, the vibration due to the shifting of weight induces micro cracks into the bridge structure (both in steel and concrete). These cracks, even after repairs, do weaken the bridge to the point that after a couple of hundred years or so, the entire bridge needs to be rebuilt. Also, repairing these micro stress cracks is very difficult because they are not only on the surface, but they also are within the structure, which cannot be repaired, unless the entire structure is rebuilt. I think these 5 major points would summarize the trends in bridge speeds and new plans of construction for railway bridges. Of course the ballast would play a role in reducing the vibrations, but it is only a part of the puzzle.

@@prabhatsourya3883 Thanks for a very well analyzed and detailed explanation..👍

Mera bhi same question hai

I also have the same question

Jo bridge iron cover wale hn unki weight bearing capacity uss cover ko include kar k bani h. Yaani kisi cheej ko vertical karne se wo jyada weight bear kar sakti h. Jin bridge par cover ooper nahi hota unke neeche yh structure hota h ya phir bridge ki length ek pillar se doosri pillar tak (span) kum ho toh na ooper na neeche yh structure hota h. Structure ooper banaana h ya neeche yh ground level se track ki height dekhkar tay hota h.

@@jagatprakashgarg1538 Thanks Jagat ji. 🙏

Depending on the size of the beam and the number of piers required, bridge model is decided. If it is decided that a long beam is needed due to lesser number of piers/pillars, then a truss is essential to distribute the load of the beam. For a shorter beam length, an ordinary beam bridge is sufficient to hold the weight up.

Good point

Abe wo ladka hai ladki nahi 😂😂😂

Turnbuckle couplings are used in ICF coaches. CBC are used in freight & LHB coaches. Only advantage i see in Turnbuckle is that they give less jerks when train starts moving or when the train comes to a halt.

I also have the same question...Also I have seen some concrete bridge where train's speed is reduced...

@@SouravDas99911 yes... i have also seen it

Same question mera v hai sir

Good question

Because they are ballestless track , which consists of less joints or negligible joints on tracks unless there is a cross over, which makes the tracks and train more stable that's why metro use these type of tracks . These ballestless tracks also used in Japanese and Chinese high speed elevated corridor .

Pagidipalli junction in between Secunderabad jn and kazipet jn in SOUTH CENTRAL RAILWAY where it seperate to guntur jn via Nalgonda And there is no platform and no train stop there.