"helper grade" meaning in English

{
  "forms": [
    {
      "form": "helper grades",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "helper grade (plural helper grades)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "American English",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "langcode": "en",
          "name": "Rail transportation",
          "orig": "en:Rail transportation",
          "parents": [],
          "source": "w"
        }
      ],
      "examples": [
        {
          "bold_text_offsets": [
            [
              142,
              154
            ]
          ],
          "ref": "1960 November, David Morgan, “\"Piggyback\"—U.S. success story”, in Trains Illustrated, page 684:",
          "text": "On February 5-6, 1960, this westbound train made its run in 25 hr. 40 min. despite falling temperatures, fog, rain, sleet and snow; a 1 in 54 helper grade to the summit of the Alleghenies; and a load of 55 cars carrying 100 trailers for a gross tonnage of 3,856 tons.",
          "type": "quote"
        }
      ],
      "glosses": [
        "A railroad gradient where helper locomotives are required to assist the train locomotives."
      ],
      "id": "en-helper_grade-en-noun-vxMdncvI",
      "links": [
        [
          "rail transport",
          "rail transport"
        ],
        [
          "railroad",
          "railroad"
        ],
        [
          "gradient",
          "gradient"
        ],
        [
          "helper",
          "helper"
        ],
        [
          "locomotive",
          "locomotive"
        ]
      ],
      "raw_glosses": [
        "(rail transport, US) A railroad gradient where helper locomotives are required to assist the train locomotives."
      ],
      "tags": [
        "US"
      ],
      "topics": [
        "rail-transport",
        "railways",
        "transport"
      ]
    }
  ],
  "word": "helper grade"
}

{
  "forms": [
    {
      "form": "helper grades",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "helper grade (plural helper grades)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "American English",
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "English terms with quotations",
        "Pages with 1 entry",
        "Pages with entries",
        "en:Rail transportation"
      ],
      "examples": [
        {
          "bold_text_offsets": [
            [
              142,
              154
            ]
          ],
          "ref": "1960 November, David Morgan, “\"Piggyback\"—U.S. success story”, in Trains Illustrated, page 684:",
          "text": "On February 5-6, 1960, this westbound train made its run in 25 hr. 40 min. despite falling temperatures, fog, rain, sleet and snow; a 1 in 54 helper grade to the summit of the Alleghenies; and a load of 55 cars carrying 100 trailers for a gross tonnage of 3,856 tons.",
          "type": "quote"
        }
      ],
      "glosses": [
        "A railroad gradient where helper locomotives are required to assist the train locomotives."
      ],
      "links": [
        [
          "rail transport",
          "rail transport"
        ],
        [
          "railroad",
          "railroad"
        ],
        [
          "gradient",
          "gradient"
        ],
        [
          "helper",
          "helper"
        ],
        [
          "locomotive",
          "locomotive"
        ]
      ],
      "raw_glosses": [
        "(rail transport, US) A railroad gradient where helper locomotives are required to assist the train locomotives."
      ],
      "tags": [
        "US"
      ],
      "topics": [
        "rail-transport",
        "railways",
        "transport"
      ]
    }
  ],
  "word": "helper grade"
}