ČSD Class T 458.1

{{one source|date=October 2016}}

{{Infobox locomotive

| name = ČSD Class T 458.1
ČD 721 / ZSSK 721

| powertype = Diesel

| image = 721 151-9 RJ.jpg

| imagesize = 250

| caption = RJ 721.151 at Praha-Smíchov station

| designer =

| builder = ČKD

| serialnumber =

| buildmodel =

| builddate = 1961–1968

| totalproduction = 221 ČD, ZSCS
49 Private owner
13 Russian Gauge

| uicclass = Bo′Bo′

| gauge = {{track gauge|sg|allk=on}}
{{track gauge|1520 mm|lk=on}}

| wheeldiameter =

| wheelbase =

| length = {{convert|13280|mm|ftin|0|abbr=on}}

| width =

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| axleload =

| weightondrivers =

| locoweight = {{convert|74|t}}

| electricsystem =

| collectionmethod =

| primemover = K 6 S 310 DR

| enginetype = (?)

| aspiration =

| displacement =

| alternator =

| generator = DC

| tractionmotors =

| maxspeed = {{convert|80|km/h|mph|0|abbr=on}}

| poweroutput = {{convert|551|kW|hp|-1|abbr=on}}

| tractiveeffort =

| factorofadhesion =

| locobrakes =

| trainbrakes =

| safety =

| operator = ČD ZSSK

| operatorclass =

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}}

ČSD Class T 458.1 is a Czechoslovak diesel locomotive. It remain in use as shunters in both Slovakia and the Czech Republic. It is now classified as class 721.{{cite book |title=Czech & Slovak Locomotives 2009 |last=Bittner |first=Jaromír |author2=Křenek, Jaroslav; Skála Bohumil; Šrámek, Milan |year=2008 |publisher=Gradis Bohemia |location=Czech Republic |isbn=978-80-86-925-06-6}}{{page needed|date=October 2016}}

The locomotive was built using the same hood arrangement and driver's cab as the T 435.0. The 6 S 310 DR diesel engine was also retained. Due to the increased weight of the units, it had a higher tractive effort despite using the same diesel engine. Except for the first five units, the locomotive had an extended wheelset using swing arms with helical spring suspension, offering improved running characteristics.{{cite web|language=cs|url=https://www.cdnostalgie.cz/vozidla/motorove-lokomotivy/-34027/ |title=Motorová lokomotiva T 458.1 "Velký hektor"|website=cdnostalgie.cz|access-date=19 June 2022}}

ČSD built the first 13 locomotives to wide gauge standard, then built 206 locomotives between 1963 and 1965 to standard gauge. The type was also successful in the export market; in addition to the Soviet Union, it was also supplied to Albania, India, Iraq, East Germany and Poland.