Please read the following table in HTML format from a webpage and then answer the question in detail according to the table. Each table cell is defined by a <td> and a </td> tag. Each table row starts with a <tr> and ends with a </tr> tag. 'rowspan=m' and 'colspan=n' represents a cell spaning over 'm' rows and 'n' columns.

Webpage title:
BHP Newcastle 37 class
Table title:
Class list
Table:
<table id='hittask' contenteditable='False'>
<tr> <th colspan=1 rowspan=1 > Locomotive </th><th colspan=1 rowspan=1 > Builder's No. </th><th colspan=1 rowspan=1 > Entered service </th><th colspan=1 rowspan=1 > As Built Engine </th><th colspan=1 rowspan=1 > Body Widened </th><th colspan=1 rowspan=1 > Withdrawn </th><th colspan=1 rowspan=1 > Notes </th></tr>
<tr> <td colspan=1 rowspan=1 > 37 </td><td colspan=1 rowspan=1 > 2121-001 </td><td colspan=1 rowspan=1 > 13 Jul 1960 </td><td colspan=1 rowspan=1 > Cummins NHS 6 </td><td colspan=1 rowspan=1 > Not widened </td><td colspan=1 rowspan=1 > 16 Jun 1987 </td><td colspan=1 rowspan=1 > Scrapped </td></tr>
<tr> <td colspan=1 rowspan=1 > 38 </td><td colspan=1 rowspan=1 > 2121-001 </td><td colspan=1 rowspan=1 > 18 Jul 1960 </td><td colspan=1 rowspan=1 > Cummins NHS 6 </td><td colspan=1 rowspan=1 > Not widened </td><td colspan=1 rowspan=1 > 30 Apr 1991 </td><td colspan=1 rowspan=1 > Scrapped </td></tr>
<tr> <td colspan=1 rowspan=1 > 39 </td><td colspan=1 rowspan=1 > 2121-003 </td><td colspan=1 rowspan=1 > 20 Jul 1960 </td><td colspan=1 rowspan=1 > Cummins NHS 6 </td><td colspan=1 rowspan=1 > Not widened </td><td colspan=1 rowspan=1 > 30 Apr 1991 </td><td colspan=1 rowspan=1 > Scrapped </td></tr>
<tr> <td colspan=1 rowspan=1 > 40 </td><td colspan=1 rowspan=1 > 2121-004 </td><td colspan=1 rowspan=1 > 15 Aug 1960 </td><td colspan=1 rowspan=1 > Cummins NHS 6 </td><td colspan=1 rowspan=1 > Not widened </td><td colspan=1 rowspan=1 > 1 Nov 1982 </td><td colspan=1 rowspan=1 > Scrapped </td></tr>
<tr> <td colspan=1 rowspan=1 > 41 </td><td colspan=1 rowspan=1 > 2121-005 </td><td colspan=1 rowspan=1 > 18 Aug 1960 </td><td colspan=1 rowspan=1 > Cummins NHS 6 </td><td colspan=1 rowspan=1 > Not widened </td><td colspan=1 rowspan=1 > 30 Apr 1991 </td><td colspan=1 rowspan=1 > Scrapped </td></tr>
<tr> <td colspan=1 rowspan=1 > 42 </td><td colspan=1 rowspan=1 > 3456-006 </td><td colspan=1 rowspan=1 > 24 Oct 1960 </td><td colspan=1 rowspan=1 > Cummins NHS 6 </td><td colspan=1 rowspan=1 > Mar 1967 </td><td colspan=1 rowspan=1 > 2 Oct 1983 </td><td colspan=1 rowspan=1 > Preserved Richmond Vale Railway Museum </td></tr>
<tr> <td colspan=1 rowspan=1 > 43 </td><td colspan=1 rowspan=1 > 3456-007 </td><td colspan=1 rowspan=1 > 24 Oct 1960 </td><td colspan=1 rowspan=1 > Cummins NHS 6 </td><td colspan=1 rowspan=1 > Jan 1968 </td><td colspan=1 rowspan=1 > ? </td><td colspan=1 rowspan=1 > Preserved Richmond Vale Railway Museum </td></tr>
<tr> <td colspan=1 rowspan=1 > 44 </td><td colspan=1 rowspan=1 > 3456-008 </td><td colspan=1 rowspan=1 > 10 Nov 1960 </td><td colspan=1 rowspan=1 > Cummins NHS 6 </td><td colspan=1 rowspan=1 > Feb 1968 </td><td colspan=1 rowspan=1 > 26 May 1983 </td><td colspan=1 rowspan=1 > Scrapped </td></tr>
<tr> <td colspan=1 rowspan=1 > 45 </td><td colspan=1 rowspan=1 > 3456-009 </td><td colspan=1 rowspan=1 > 14 Nov 1960 </td><td colspan=1 rowspan=1 > Cummins NHS 6 </td><td colspan=1 rowspan=1 > Jan 1966 </td><td colspan=1 rowspan=1 > 2 Jan 1982 </td><td colspan=1 rowspan=1 > Scrapped </td></tr>
<tr> <td colspan=1 rowspan=1 > 46 </td><td colspan=1 rowspan=1 > 3456-010 </td><td colspan=1 rowspan=1 > 1 Dec 1960 </td><td colspan=1 rowspan=1 > Cummins NHS 6 </td><td colspan=1 rowspan=1 > Apr 1966 </td><td colspan=1 rowspan=1 > 11 Jan 1982 </td><td colspan=1 rowspan=1 > Scrapped </td></tr>
<tr> <td colspan=1 rowspan=1 > 47 </td><td colspan=1 rowspan=1 > 3456-011 </td><td colspan=1 rowspan=1 > 8 Dec 1960 </td><td colspan=1 rowspan=1 > Cummins NHS 6 </td><td colspan=1 rowspan=1 > Oct 1966 </td><td colspan=1 rowspan=1 > 1 Jul 1991 </td><td colspan=1 rowspan=1 > Preserved Dorrigo Steam Railway & Museum </td></tr>
<tr> <td colspan=1 rowspan=1 > 48 </td><td colspan=1 rowspan=1 > 4970-012 </td><td colspan=1 rowspan=1 > 22 Sep 1961 </td><td colspan=1 rowspan=1 > Rolls Royce C6TFL </td><td colspan=1 rowspan=1 > Aug 1966 </td><td colspan=1 rowspan=1 > 30 Sep 1999 </td><td colspan=1 rowspan=1 > Sold Manildra Group Dec 2002 as MM04 </td></tr>
<tr> <td colspan=1 rowspan=1 > 49 </td><td colspan=1 rowspan=1 > 4970-013 </td><td colspan=1 rowspan=1 > 29 Sep 1961 </td><td colspan=1 rowspan=1 > Rolls Royce C6TFL </td><td colspan=1 rowspan=1 > Feb 1966 </td><td colspan=1 rowspan=1 > 30 Sep 1999 </td><td colspan=1 rowspan=1 > Sold Loongana Lime Sep 2002 </td></tr>
<tr> <td colspan=1 rowspan=1 > 50 </td><td colspan=1 rowspan=1 > 4970-014 </td><td colspan=1 rowspan=1 > 14 Oct 1961 </td><td colspan=1 rowspan=1 > Rolls Royce C6TFL </td><td colspan=1 rowspan=1 > Dec 1967 </td><td colspan=1 rowspan=1 > 30 Sep 1999 </td><td colspan=1 rowspan=1 > Sold Loongana Lime Feb 2002 </td></tr>
<tr> <td colspan=1 rowspan=1 > 51 </td><td colspan=1 rowspan=1 > 4970-015 </td><td colspan=1 rowspan=1 > 3 Nov 1961 </td><td colspan=1 rowspan=1 > Rolls Royce C6TFL </td><td colspan=1 rowspan=1 > Oct 1967 </td><td colspan=1 rowspan=1 > 30 Sep 1999 </td><td colspan=1 rowspan=1 > Sold Manildra Group Dec 2002 as MM03 </td></tr>
<tr> <td colspan=1 rowspan=1 > 52 </td><td colspan=1 rowspan=1 > 4970-016 </td><td colspan=1 rowspan=1 > 14 Dec 1961 </td><td colspan=1 rowspan=1 > Rolls Royce C6TFL </td><td colspan=1 rowspan=1 > Sep 1966 </td><td colspan=1 rowspan=1 > 1 Jan 1988 </td><td colspan=1 rowspan=1 > Preserved Dorrigo Steam Railway & Museum </td></tr>
<tr> <td colspan=1 rowspan=1 > 53 </td><td colspan=1 rowspan=1 > 9211-018 </td><td colspan=1 rowspan=1 > 16 Apr 1964 </td><td colspan=1 rowspan=1 > Rolls Royce C6TFL </td><td colspan=1 rowspan=1 > Jun 1967 </td><td colspan=1 rowspan=1 > 30 Sep 1999 </td><td colspan=1 rowspan=1 > Preserved Richmond Vale Railway Museum </td></tr>
<tr> <td colspan=1 rowspan=1 > 54 </td><td colspan=1 rowspan=1 > 3835-020 </td><td colspan=1 rowspan=1 > 5 Jan 1966 </td><td colspan=1 rowspan=1 > Cummins NHS 6 </td><td colspan=1 rowspan=1 > built wide </td><td colspan=1 rowspan=1 > 30 Sep 1999 </td><td colspan=1 rowspan=1 > Preserved Richmond Vale Railway Museum </td></tr>
<tr> <td class="highlighted"  colspan=1 rowspan=1 > 55 </td><td colspan=1 rowspan=1 > 3275-051 </td><td colspan=1 rowspan=1 > 8 Sep 1977 </td><td class="highlighted"  colspan=1 rowspan=1 > Cummins NT855L4 </td><td colspan=1 rowspan=1 > built wide </td><td colspan=1 rowspan=1 > 30 Sep 1999 </td><td class="highlighted"  colspan=1 rowspan=1 > Sold Junee Railway Workshop Jul 2002 </td></tr>
<tr> <td class="highlighted"  colspan=1 rowspan=1 > 56 </td><td colspan=1 rowspan=1 > 2967-052 </td><td colspan=1 rowspan=1 > 11 Nov 1977 </td><td class="highlighted"  colspan=1 rowspan=1 > Cummins NT855L4 </td><td colspan=1 rowspan=1 > Narrow body </td><td colspan=1 rowspan=1 > 1 Jun 1988 </td><td class="highlighted"  colspan=1 rowspan=1 > Scrapped </td></tr>
<tr> <td class="highlighted"  colspan=1 rowspan=1 > 57 </td><td colspan=1 rowspan=1 > 6606-182-057 </td><td colspan=1 rowspan=1 > 13 Dec 1982 </td><td class="highlighted"  colspan=1 rowspan=1 > Cummins NT855L4 </td><td colspan=1 rowspan=1 > built wide </td><td colspan=1 rowspan=1 > 30 Sep 1999 </td><td class="highlighted"  colspan=1 rowspan=1 > Sold Junee Railway Workshop Jul 2002 </td></tr>
<tr> <td class="highlighted"  colspan=1 rowspan=1 > 58 </td><td colspan=1 rowspan=1 > 6606-182-058 </td><td colspan=1 rowspan=1 > 13 Apr 1983 </td><td class="highlighted"  colspan=1 rowspan=1 > Cummins NT855L4 </td><td colspan=1 rowspan=1 > built wide </td><td colspan=1 rowspan=1 > 30 Sep 1999 </td><td class="highlighted"  colspan=1 rowspan=1 > Sold Heggies Bulk Haul, Port Kembla 4 Oct 1999, renumbered HBL58, sold to Manildra Group </td></tr>
</table>
Question:
When was that Cummins engine model discontinued?
Answer:
The locos powered with Cummins NT855 engines were either scrapped or sold.