thumb|Photo of a model Sharopoyezd, 1932
The Sharopoyezd (; literally "ball-bearing train"), also known as ShELT (, acronym for шаро-электро-лотковый транспорт, "ball-bearing electric trough transport") was a Soviet attempt to develop a high-speed rail system in the 1930s. Instead of iron rails, the design specified a single, large concave rail made of concrete.
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).