Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| Class | Wheel arrangement | LCDR number(s) | SECR numbers | Manufacturer | Year made | Quantity made | Quantity preserved | Year(s) withdrawn |
| --- | --- | --- | --- | --- | --- | --- | --- | --- |
| William Kirtley (1874–1898) | William Kirtley (1874–1898) | William Kirtley (1874–1898) | William Kirtley (1874–1898) | William Kirtley (1874–1898) | William Kirtley (1874–1898) | William Kirtley (1874–1898) | William Kirtley (1874–1898) | William Kirtley (1874–1898) |
| A | 0-4-4T | 65–70, 101–112 | 524–529, 560–571 | Vulcan Foundry Neilson & Co. | 1875 | 18 | 0 | 1915–1926 |
| A1 | 0-4-4T | 163–174 | 622–633 | Kitson & Co. | 1880 | 12 | 0 | 1923–1926 |
| A2 | 0-4-4T | 75–80 | 534–539 | Robert Stephenson & Co. | 1883–1884 | 6 | 0 | 1925–1926 |
| R | 0-4-4T | 199–216 | 658–675 | Sharp, Stewart & Co. | 1891 | 18 | 0 | 1940–1955 |
| B | 0-6-0 | 135–140 | 594–599 | Dübs & Co. | 1876 | 6 | 0 | 1912–1915 |
| B1 | 0-6-0 | 151–156 | 610–615 | Dübs & Co. | 1877 | 6 | 0 | 1912–1924 |
| B2 | 0-6-0 | 193–198 | 652–657 | Vulcan Foundry | 1891 | 6 | 0 | 1929–1933 |
| T | 0-6-0T | 141–150 | 600–609 | Longhedge Works | 1879–1891 | 10 | 0 | 1932–1951 |
| M | 4-4-0 | 157–162 | 616–621 | Neilson & Co. | 1877 | 6 | 0 | 1911–1914 |
| M1 | 4-4-0 | 175–178 | 634–637 | Longhedge Works | 1880–1881 | 4 | 0 | 1912–1923 |
| M2 | 4-4-0 | 179–186 | 638–645 | Longhedge Works Dübs & Co. | 1884–1885 | 8 | 0 | 1912–1923 |
| M3 | 4-4-0 | 187–182, 3–8, (9–10), 12–17, 19, 20, 23–25, (26) | 646–651, 462–469, 471–476, 478, 479, 482–485 | Vulcan Foundry , Longhedge Works | 1891–1900 | 26 | 0 | 1925–1928 |
Question:
Which SECR numbers have a class of b1?
Answer:
610–615