Tennyson was a Poet Laureate, meaning he could make no negative criticism of the country, meaning the poem may be seen as a glorification and romanticism of war
'storm'd at with shot and shell'
Method - alliteration of harsh and plosive sounds, creating a painful sound on the reader's ears which underscores the barbarity and violence of the war
As Tennyson cannot make any negative comments of the war due to his Poet Lauret, perhaps this could be seen as his suggestion and recognition of the brutal nature of the battle.
'half a league, half a league'
Poem opens in media res - this thrusts the reader into the viscious nature and suddeness of the charge
Furthermore, Tennyson may also use the repetition of 'half a league' in the first stanza to create a rythm in order to immitate and echo the sound of horses charging, in order to create vivid imagery for the reader to depict the intense and barbaric nature of battle
'theirs not to make reply'
the use of anaphora in the second stanza (repetition of 'theirs not') creates ambiguity of the soldiers, showing that this was a large scale battle where many soldiers lost their life, who where uniformed in their suffering and identity.
This shows the soldier's obedience and patriotic attitudes as they willingly charge into the 'valley of death' in order to fight for their country. Perhaps Tennyson does this to praise and romanticize the soldier's efforts as he depicts them as heroic rather than as victims.
'Rode the 600'
Tennyson repeats this phrase at the end of each stanza, which starkly contrasts with the vivid imagery he creates in the rest of the poem as he depicts the horrors and brutality of the battle - however the soldiers keep going.
Tennyson perhaps does this to glorify war to show the soldier's patriotic sacrifice - however, the reader is aware of the forgotton brutal and violent deaths in which all the men died, which may lead the reader to critique Tennyson's attitude of the soldiers
'jaws of death', 'valley of death', 'mouth of hell'
personification of death to depict it as an unstoppable and brutal force which the soldier's valiantly charge into, depicting them as heroic and brave
it shows that despite the soldier's aarness that death was imminent, they abided to their order to protect their country
Perhaps Tennyson is making an attempt to manipulate the reader in order to convince them that the solider's deaths are justified as they died for their religeon and their country, however we are aware that this was not the case as the soldiers lost their lives due to a wrong command given, which therefore may evoke anger from the reader as Tennyson is wrongly glorifying the war.